Table of contents

The International Conference for Young Scientists "Issues of Physics and Technology in Science, Power Industry and Medicine" (IPTSPIM-2019) was organized by National Research Tomsk Polytechnic University (TPU) in 30 September – 5 October 2019, Tomsk, Russia.

Since 1996 Faculty of Physics (now School of Nuclear Science & Engineering) of Tomsk Polytechnic University periodically organizes International Scientific Conference "Issues of Physics and Technology in Science, Power Industry and Medicine". The next tenth conference will be dedicated to the 70th anniversary of physical and technical education at TPU. Up to the present time, more than 9000 highly qualified specialists have been trained for the nuclear industry. Today TPU, relying on its unique experience and scientific developments, continues to perform the strategic objective of training personnel for nuclear industry facilities not only in Russia, but also abroad.

This year the Conference gathered young scientists, students, experienced researchers, and invited industrial specialists working in nuclear, radiation, physical-chemical, and information technologies, as well as in automation systems, radioactive materials research, plasma and isotopes obtaining, and nuclear medicine in order to facilitate aggregation and sharing interests and results for a better collaboration in atomic power industry and development.

The major topics included

• Nuclear power installations: technology and safety.

• Radiation technologies in industry and medicine.

• Mathematical simulation and production automation.

• New materials and technologies

We want to thank all members of the Organizing Committee, TPU and everyone who contributed to the organization of this event, for their contribution towards the conference and for their contributions to this proceeding.

The Organizing Committee of IPTSPIM-2019

All papers published in this volume of Journal of Physics: Conference Series have been peer reviewed through processes administered by the proceedings Editors. Reviews were conducted by expert referees to the professional and scientific standards expected of a proceedings journal published by IOP Publishing.

The main circuitry methods for improving dynamic parameters in the large signal operation of the analog sensor interfaces (ASI) used in the instrumentation and automatic control systems are compared in the article. It is shown that the existing methods for increasing the slew rate (SR) of the ASI based on the operational amplifier (OA) are associated with the increase in the gain-crossover frequency of the OA due to the higher-frequency technologies (i.e., SiGe), or with the expansion of the range of active operation of the input subcircuit included before the integrating capacitor of the OA. A method for increasing the SR of the inverting ASI with an OA input stage of the dual-input class is proposed. The basis of the method lies in the introduction of two differentiating correction circuits (DCC) into the classical OA circuit, which in the large signal operation form additional overcharge currents of the integrating capacitance of the OA correction. In this case, the DCCs practically do not affect the low-signal amplitude-frequency characteristic of the OA. Such OAs have low current consumption in static mode and can be performed on the basis of standard processes, including radiation-hardened and low-temperature ones (CMOS, SOI, SOS, BiJFet, BJT, SiGe and others). The BJT OA computer simulation results show that the inverting ASI SR increases from 170 to 1800 V/μs. We consider the promising architectures of the high-speed OAs with the DCCs providing an increase in the SR in both inverting and non-inverting ASIs. The proposed ASI circuitry is designed to be used in automation devices and control systems, including nuclear and energy facilities.

The possibility of improving the basic properties of a lubricating composition based on Litol 24 lubricant, by adding nanopowders (molybdenum, tungsten carbide, tungsten) obtained from their carbide wastes, has been considered. The structure of nanopowders has been studied. Their X-ray spectrum analysis was carried out It has been shown that the addition of a molybdenum nanomodifier to the base lubricant mixture results in improved tribotechnical properties. The optimal concentration of molybdenum nanopowder was determined to be 0.1 wt%. Also paper contains results of operational tests of lubricant composition. The resulting lubricant composition may be a competitive product in the lubricant market

The paper presents studies of the use of the biological leaching method for the processing of molybdenum-containing alloys (production waste). As a result, we can obtain economically viable and environmentally safe technology for the processing of molybdenum-containing wastes.

We consider a circuit design method to increase a slew rate increase and transient process setting time decrease in buffer amplifiers (BAs), intended for operation in analog interfaces of physical values sensors and automatic devices at low temperatures. Differentiating transient correction circuits are introduced into the classical circuits of the BAs on complementary field-effect transistors (CJFETs) to improve these dynamic parameters. We investigated two buffer amplifier's topologies: single-ended and balanced ones. The article shows the practical use of the proposed BA in the output and input stages of the high-speed operational amplifiers.

The article is dedicated to experimental and theoretical studies characteristics flame propagation in combustion chamber internal combustion engine with spark ignition and their influence on completeness combustion. It is theoretically and experimentally proved that relationship of flame propagation characteristics with completeness of combustion composite fuel is complex, non-linear, and depends on chemical composition combustible mixture and temperature in combustion chamber. It was revealed that an increase thickness near-wall unburned fuel layer, size of slots in combustion chamber and surface area of combustion chamber contribute to a reduction combustion efficiency of the fuel. It is shown that an increase rate flame propagation and a decrease thickness flame front leads to an increase completeness combustion fuel. It was revealed that proposed formula, using fundamental characteristics of flame propagation, allows to us calculating completeness combustion composite fuel. This indicates feasibility using this formula at the design stage and fine-tuning low-emission and energy-efficient combustion chambers of engines and power plants.

The paper examines carbon 0.5-1µ thick coatings obtained through various physical vapour deposition and chemical vapour deposition methods on stainless steel and tool steel substrates. Their composition, morphology and physical properties have also been studied. The correlations of erosive wear resistance and H³/E²ratio (where H is hardness and E is elastic modulus) have been identified for carbon coatings in regards to the production method. Ta-C carbon coatings demonstrate high resistance to dynamic loads with erosive wear in a sand-blast machine.

This paper is devoted to proposing a new approach to the synthesis of SiC- and Ti₃SiC₂-based ceramics by using of preceramic paper as a feedstock. A preceramic paper with SiC and Ti₃SiC₂ powder fillers were sintered by spark plasma sintering (SPS) method for holding time 10 minutes under pressure 20-100 MPa. The temperature for the sintering of SiC- and Ti₃SiC₂-filled paper was 2073-2373 K and 1373-1473 K respectively. The influence of sintering parameters on the materials microstructure was analyzed by scanning electron microscopy. It was revealed that with an increase in pressure from 20 to 100 MPa, the microstructure of the materials becomes denser. It agrees with the results of measuring the density of the sintering materials by the hydrostatic weighting. The determination of Young`s modulus by the acoustic method demonstrates that with the increase of the applied pressure during SPS, Young's modulus of the synthesized SiC- and Ti₃SiC₂-ceramics increase.

Cardiac examinations are becoming increasingly common among all segments of the population. For a more accurate diagnosis, such tools as an electrocardiogram, ultrasound of the heart muscle, as well as computed tomography are used. To understand the processes that occur when a pathology occurs, it was decided to implement the mathematical and 3D models of the heart muscle that are interconnected. These models are individualized. The work of the heart is presented without a hemodynamic system, so the contraction processes are set using programmable spring pistons. The mathematical model was implemented in the MatLab software package. The paper describes the main problems that arose when creating a 3D model of the heart, and how to solve them. The development of the 3D model was carried out in the 3ds Max program, with the help of which not only the model was built, but also the parameterization of the model was considered according to the calculations. This experimental software aims to facilitate the diagnosis and detection of cardiac diseases.

Report is devoted to investigations of graphene meta–surfaces for the transmission of radiation induced by plasmons in subTHz and THz ranges, cell of which consists of structures based on graphene ring and graphene nano–tape. It create regimes of radiation transmission – transparency windows induced by electric dipole resonances. Resonant frequency of transparency window can be dynamically tuned in wide band of subTHz and THz bands by changing the chemical potential (Fermi energy) of graphene by applying external electric field (gating) instead of re–fabricating of structures. Questions of possibilities of electronic controlled filters creating of subTHz and THz bands grounded on different configurations of graphene meta–surfaces are discussed; their characteristics and frequency dependencies are investigated. Mathematical modelling and electrodynamic calculation of the filters characteristics of subTHz and THz bands grounded on multilayer structures of "graphene–dielectric" type are carried out. From results of mathematical modelling it follows that periodic layered microstructures "graphene–dielectric" type can be used for creation of subTHz and THz bands broadband filters of planar construction, controlling by electric field and fast tuning at small changes in Fermi energy level of graphene.

The current threshold elements of direct and reverse cyclic shift are developed. This logical elements are recommended as memory elements for the construction of relevant controllers and devices for tolerance control of analog signals, which used in diagnosis of complex electronic equipment. The mathematical apparatus used in the design is a linear algebra. The basic equations and results of computer modeling of the developed cyclic shift schemes are presented. Computer simulation was carried out in the Cadence environment on models of field-effect transistors XB06.

Two new architectures of the third-order low-pass filters (LPF) based on differential (Op-Amp) and differential difference amplifiers (DDA) with a paraphase output are compared. This architectures designed for practical use as anti-aliasing filters in analog-to-digital converters of sensor signals of various physical quantities. The basic equations of the developed LPF modifications that make possible to perform their parametric synthesis are given. The computer simulation results are presented, which show that the LPFs under consideration provide the guaranteed frequency response (FR) attenuation outside the bandwidth being implemented on Op-Amps by Analog Device (AD8132) and Texas Instruments (THS4131).

The paper deals with the effect of synthesis parameters on the reactivity of Fischer– Tropsch iron-based catalyst resulting from electrical wire explosion in a carbon monoxide medium. The technology provides the synthesis of ultrafine particles with a large specific surface area and a given phase composition. A mixture resulting from the synthesis of liquid hydrocarbons contains hydrocarbons of a paraffinic and aromatic structure, and its further use requires additional refinement.

The influence of the shielding gas composition and the non-consumable electrode construction on the total and effective efficiency of welding was studied. It was found that value total efficiency is at minimum at 25 % helium content and is increasing with the He concentration growth in the gas mixture. The alteration of arc force impact on the welded metal depending on the current rate, shielding gas composition and cathode processing history was demonstrated. It was found that the arcs with a focused cathode spot feature higher value of the integral forced impact on the welded metal, comparing to the arcs with a diffuse cathode spot, regardless the shielding gas composition.

It was demonstrated that applying the flux paste on the back side of the welded joint during welding low-alloyed steels provides control over the sizes of the root and its defect-free formation. It was found that the back bead width is vital to unsupported root formation of thin-walled articles for the considered welding modes.

Studies on the magnetic isotopes effect of zinc ⁶⁷Zn and magnesium ²⁵Mg on the adenosine triphosphate (ATP) concentration in living organisms were held in this work on the example of E. coli bacteria. External static magnetic fields 0-100 mT were used to enhance the effect of magnetic isotopes on intracellular processes. Enrichment of microorganisms with magnesium or zinc isotopes during growth changes the ATP concentration in cells depending on the type of isotope – magnetic or non-magnetic. The effect of weak magnetic fields of 0-10 mT stimulates the bacterial cell growth and the intracellular ATP concentration change. The maximum concentration of ATP was achieved by using a magnetic isotope of magnesium ²⁵Mg and exposure of bacteria to the static magnetic fields 70-90 mT. Non-magnetic isotopes of magnesium or zinc and magnetic fields other than the ranges 0-10 and 70-90 mT can be used to decrease the rate of ATP synthesis.

Magnetic isotope effects of magnesium ²⁵Mg on antibiotic resistance and biofilm formation of bacteria E. coli were discovered. The increase in antibiotic resistance in the presence of the ion ²⁵Mg²⁺ was registered for E. coli cells incubated with quinolones, indicating the inhibiting effect of the magnetic moments of nuclei ²⁵Mg on deoxyribonucleic acid (DNA) synthesis. It was discovered that the process of biofilm formation by the bacteria E. coli is magnetosensitive. Magnetic magnesium isotope presence in nutrient media stimulated formation of biofilm compared with nonmagnetic isotopes ^{24, 26}Mg. As e result the enrichment of media by magnetic magnesium can be used to control the physiological properties of bacteria: biofilm formation and antibiotic resistance.

Analytical and simulation models of pitting corrosion on chromium-nickel steels under galvanostatic and potentiostatic polarization conditions are proposed. Under conditions of galvanostatic polarization three modes of local metal dissolution have been found. The labeled state graph which shows the transitions of a system from one dissolution mode to another has been offered. The values of stable pit formation time have been calculated. The additional model parameter «fraction of the pits being passivated» applied to establish the correlation between pit initiation and pit passivation rates in a stochastic model is proposed. It explains the variable dependence of a polarization potential on a pit repassivation rate.

The paper considers safety ensuring issues during the work at the plant intended for researching the technology of irradiated beryllium purification using chlorination method. Presented technology assumes handling beryllium and its compounds, chlorine and hydrogen chloride in compliance with the following safety aspects: radiation and toxic safety. Based on the results of the calculation of an expected dose and taking into account the requirements for the attended personnel, the allowable duration of maintenance the reaction chamber with the loaded irradiated beryllium sample was determined. The amount of radioactive beryllium in each cleaning cycle was determined from the point of view of the reasonable minimization (based on the safety rules) of the possible internal exposure of personnel due to the intake of gaseous tritium. The paper describes a unique way to measure the concentration of free chlorine by optical method and methods to protect the harmful effects of chlorine gas and hydrogen. The results of this study demonstrate possibility of safe technology implementation during preparation and conduction of experiments for the treatment of irradiated beryllium.

The preparation of multicomponent coatings based on silicon and yttrium on the niobium substrate was investigated. Y-Si/NbSi₂ coatings on the Nb substrate by currentless deposition in molten salts were produced. The preparation of NbSi₂ layers is carried out in NaF-NaCl-Na₂SiF₆ melts with the addition of Si powder. The preparation of Y-Si layers is carried out in NaCl-KCl-YF₃ melts containing Y powder. Coating samples are studied using SEM. It is established that sequentially synthesized coatings are characterized by a two-layer structure. Using the EDS method, the chemical composition of the obtained layers is established: Y – 26.68; Nb – 62.55; Si – 10.76 wt. %. The oxidation test of the obtained coatings Y-Si/NbSi₂ on Nb samples is performed. It is found that testing at 1200 ˚C for 2 hours leads to a mass loss of 62 mg/cm²·h.

The purpose of this paper is simulation parameters of human walking in normal and pathological conditions. Modeling does possible to determine dynamic characteristics of motion and to optimize designs of walking mechanisms, prostheses, orthoses, implants and more. In developing the model of human walking, we used a special case of the Lagrange equation of the second kind. The experiment was conducted by video analysis of real gait of people of different ages and sex. As a result of the simulation the speeds and accelerations of all links of the model, moments in joints, and peak values of moments are determined. Simulation of human walking makes it possible to develop technical specifications for the design of walking mechanisms, prostheses, implants and more.

In this investigation, the interaction of metallic palladium with potassium tetrafluorobromate was examined in open system, the reaction products were identified using X-ray phase analysis. A thermogram of the interaction of Pd with KBrF₄ was obtained, the temperature range of the reaction (187.9-328°C) and the thermal effect (431.31 J/g) were determined. It was found that the fluorination process is a multi-stage process. The solubility of the obtained K₂PdF₆ compound in nitric and hydrochloric acids was investigated. The process of extraction of palladium from nitric acid solutions with tributyl phosphate was carried out and the influence of the concentration of palladium and the acidity of the initial solution on the distribution coefficient was investigated.