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The long-term stability of well-known TVO sensors before and after gamma irradiation was investigated during almost 17 years. Five of six sensors, calibrated in the temperature range from 3 to 300 K, were selected according to a requirement of their relative accuracy ΔT/T ≤ ± 0.25% at the cryogenic temperature range. Long-term stability measurements made 7.5 years after calibration are in good agreement with this value at 293, 77.3, and 4.2 K. Then these sensors and the sixth sensor, taken as the “worst” one for comparison, were irradiated by the 60Co gamma source at room temperature up to the total dose of about 1 MGy. Noticeable relative temperature shifts (more than ± 0.25%) are revealed for all the sensors after irradiation, and this fact is explained based on the model of structural changes in the volume of the sensitive element. Post-irradiation measurements carried out during 9 years at 293, 77.3, and 4.2 K indicate good stability of the sensors after irradiation.

The operation of a gamma densitometer (GD) of ID = 100 mm is considered; it is intended for the diagnostics of three-phase oil–water–gas flows using the separationless method, when the composition of components is determined by a spectrometric analysis of gamma irradiation with two different photon energies. The 241Am and 137Cs isotopes, installed in the same housing, are used as gamma sources, while a gamma detector is made on the basis of the BGO crystal of 40 mm in diameter and height. Information about the design, measuring electronics, and main characteristics of the GD is given. The method used for the temperature stabilization of the recorded radiation intensities for both isotopes within a range of ambient temperature from 10 to 35oC is presented.

The article presents studies carried out on a group of rats in order to determine the influence of the morphological characteristics of animals on the conduct of general inhalation anesthesia. It was found that if the rules for the preparation of animals, dosage of drugs (due to the physiological characteristics of rats), as well as proper care of animals after anesthesia are observed, the risk of complications, up to death, is reduced to a minimum.

The paper deals with the design of circular and disk saws with different structural design, two of which have a patent of the “Technology of machine building” Department; performed theoretical development to determine the cutting power different from the standard method; the result of a production experiment for analyzing the cutting mode of aluminum pipes on the Italian cutting line. The results of the work are used in the educational process of the University.

The influence of modification of heat-resistant nickel-based alloys on the crystallization kinetics of alloys was established by the methods of thermal analysis. This effect is expressed in the increase in solidus temperature and, as a consequence, narrowing the crystallization range of the alloy, the increase in the growth rate of a solid solution, and change in the temperature of precipitation of eutectic and strengthening phases. As a result, the use of modification with refractory particles makes it possible to exert an additional effect on the structure and properties of nickel-based alloys without additional heat treatment

Credible data on the actual characteristics of thin-film platinum temperature sensors with a nominal value of 1000 Ω in a wide temperature range of 3.8–370 K derived from long-term experimental studies of a large batch of 130 sensors are presented (most likely, for the first time). These characteristics are the temperature dependence of resistance, sensitivity, short-term and long-term stability, response to thermal cycling in the 293–77.3 K range, thermal resistance in liquid nitrogen and helium, measurement accuracy and interpolation polynomials, and gamma-radiation resistance. The calibration data are compared to the DIN EN 60751 standard and equivalent information for a pure platinum sensor. It is demonstrated that the actual parameters of sensors of the studied type are better than the datasheet ones: contrary to literature data, the measurement accuracy at cryogenic temperatures improves as the temperature decreases. Ways to increase the accuracy rating of these sensors are discussed. Data on their practical application in the XFEL superconducting accelerator project (Hamburg) and other projects are also provided.

When mining hard coal the underground method is prevailed. This method provides a higher quality of the mineral. Methane emissions occur in coal mines during the development of gasbearing seams. These emissions are the reason for the formation of an explosive mixture when mixed with mine air, and also contribute to the spontaneous combustion of coal. Methane alarms are used to monitor the mine atmosphere. Thermocatalytic sensor is the main element of such a gas analyzer. The sensor is placed in a breathable housing. This body is called a flame arrester. This article discusses the possibility of replacing the material used for the manufacture of a flame arrester. The basis of the existing material is nickel powder. It is proposed to replace it with a cermet bond. The composition of the ceramic material of the part is developed by the author and presented in the article. Replacement of material will lead to a significant reduction in the cost of the part and simplification of the manufacturing technology

Possible extreme fluctuations of sea level in the area of the Akkuyu nuclear power plant induced by tsunami, wind, waves, and tides are discussed. The probability characteristics of dangerous sea-level rise in the area are estimated using hydrodynamic modeling and historical data.

Mining of a horizontal isolated seam in a uniform medium in plane strain conditions is considered. The stress distribution in roof rocks of the coal seam is obtained at different stages of mined-out area development. The stresses are governed by the complex-variable function, which allows determining location and configuration of zones of stress relaxation and additional load in rock mass. This information is required for estimation of induced jointing and formation of gas pockets in the coal seam parting. The use of the analytical solution makes it possible to obtain relations for finding stress concentration factors and to present the related parameters as contour lines.

The characteristics of two kinds/types of well-known TVO sensors are compared. They differ, probably, with respect to the quality of initial components and the shade of their green ceramic coating. Detailed information about long-term stability of the first kind of sensors are presented 10 years after calibration for a fairly large group of 52 pieces at room temperature, in liquid nitrogen and liquid helium, at atmospheric pressure and at Ts ≈ 1.9 K. Another group of 31pieces similar sensors was tested 15 years after calibration at room temperature, in liquid nitrogen and in liquid helium at atmospheric pressure. These sensors are based on TVO resistors produced previously, in the year 1991. Sixty pieces of the second kind of TVO resistors produced in 2009 were thermo-cycled between room temperature and 77.3 K, and two groups of 7 and 9 pieces were selected for test on their stability during 2.5 years at room temperature, in liquid nitrogen and in liquid helium at atmospheric pressure. A comparison shows noticeably better performances for the first kind of TVO resistors of dark green color. In particular, their sensitivity is roughly twice as high at liquid helium temperature. Information regarding the stability of well-known Cernox Cx-1030 sensors 9 years after calibration is also presented for comparison.

The study established impacting of regional activities of social economic incentives of medical personnel on the process of employment in medical institutions of rural area. The analysis of Federal and regional legislation regulating process of incentives of physicians to employment in rural health care system was implemented. The study material was based on the results of implementation of activities of social economic incentives of medical personnel to join rural medical institutions applied in the territory of the Nizhny Novgorod region in 2006-2017. The comparative analysis was implemented concerning normative base of activities of social economic support of physicians including assessment of quality and scope of material preferences and also analysis of effect of types of material incentives on amount of input of specialists in rural health care. The comparative characteristics are presented concerning regional activities of supporting rural medical personnel with ready-made accommodation and vehicles and also assessment of federal activities related to granting rural physicians with single compensation payment of one million rubles. The implemented study demonstrated that problem of recruitment of medical personnel in general and in rural health care in particular is an extremely complicated task. The Federal and regional health authorities were engaged in development of alternatives of solution of this problem until now. It is established that a significant importance in decision making related to employment in rural medical institutions is attached to implementing programs of social economic support. It is derived that measures of social economic support related to granting ready-made accommodation within the framework of regional activities favored more active involvement and long-term assignment of medical personnel in rural area than granting with single compensation payment of one million rubles.

The article presents the results of questionnaire survey of physicians concerning issues of prevention and dispensary observation of а-HCV/HBsAg positive patients. The study established inadequate awareness and medical activity of physicians concerning issues of prevention and dispensary observation of patients from risk group and patients with viral hepatitis C/B. The working experience and medical length of service without any additional training give no guarantees of sufficient knowledge in issues of prevention, timely detection and corresponding observation of a-HCV/HBsAg positive patients.

Clinical following-up of children born to a-HCV/HBSAg-positive women referred to a risk group for vertical transmission of hepatitis C/B viruses is one of the most important areas of medical care for this group of patients. The data of the analysis of the organization, quality and effectiveness of dispensary observation of children from the «risk groups» for the vertical transmission of HCV/HBV infection are presented. The unsatisfactory quality and effectiveness of the dispensary observation of this category of patients has been established. Inadequate medical activity and awareness of doctors on the prevention of parenteral viral hepatitis have been identified. There is substantiated the necessity of implementing a multi-level system for the prophylaxis of viral hepatitis C/B in a system encompassing both a child and a mother based on continuity at each of its stages, which will allow reduce the number of infected children of younger age groups.

Introduction. The incidence of chronic viral hepatitis C in women is determine the relevance of the infection vertical transmission to children with the outcome to chronic viral hepatitis C. It is necessary to assess the effectiveness of current measures to prevent perinatal viral hepatitis C and to develop strategy for prevention viral hepatitis C in children for future. Aim: to evaluate the organization and putting into effect the prevent of perinatal viral hepatitis C in an outpatient setting. Material and methods: authors presents the results of questionnaire survey of а-HCV-positive children’s mothers with chronic perinatal viral hepatitis C. The analysis of the results was carried out using Cohen Kappa method, Cohen Kappa consent coefficient (κ) was calculated. Results: The study established inadequate organization and implementation of measures to provide medical care for the prevention of perinatal viral hepatitis C int all stages of ambulatore care. Conclusion: it is necessary to create a multi-level system of prevention of viral hepatitis C in children.

Objective: to study the basic characteristics of changes revealed by MRI in patients with syringomyelia associated arachnopathy before and after surgery.Materials and methods. MRI was performed in 58 pat ients with syringomyelia before and after surgery in period from 2013 to 2016.Results.The diagnosis “syringomyelia” was approved in 41 patients. There was huge regression (more than 50% of volume) of syringomyelia cavity in 17 (41.4%) patients. In 20 (48.7%) patients marked decrease in size syringomyelia cavity (less than 50%), the volume expansion of the front and rear of cerebrospinal fluid spaces.Conclusions. The use of modern MRI Protocol in various types of syringomyelia allows not only to detect and give a comprehensive feature cavities, but also to detect adhesions, location and length, as well as to assess the dynamics of the disease after surgical treatment.

This paper is a review of our works on implementation of measuring systems for two-phase helium, hydrogen, liquefied natural gas (LNG) and oil production. In principle, two-phase flow-meters combining void fraction radio-frequency (RF) sensors and narrowing devices are considered in details. In particular, they can be applied for superconducting accelerators cooled with two-phase helium, refueling hydrogen system for space ships and some applications in LNG production industry. To produce these cryogenic two-phase flow-meters it is necessary to combine such devices as low temperature sensors, cryogenic void fraction sensors, sensors responsive to average velocity of the two-phase flow, pressure sensors and electronics to measure their signals. The measuring systems for two-phase liquefied natural gas (LNG), and oil-formation/salty water flows are also presented. These systems are based on combination of a gamma-densitometer and a narrowing device. It is shown as well that the experience gained allows separationless flow-meter for three-phase oil-gas- formation water flows to be produced.

This paper is a review on implementation of measuring systems for two-phase helium, hydrogen, liquefied natural gas (LNG), and oil-formation/salty water flows. Two types of such systems are presented. The first type is based on two-phase flow-meters combining void fraction radio-frequency (RF) sensors and narrowing devices. They can be applied for superconducting accelerators cooled with two-phase helium, refueling hydrogen system for space ships and some applications in oil production industry. The second one is based on combination of a gamma-densitometer and a narrowing device. These systems can be used to monitor large two-phase LNG and oil-formation water flows. An electronics system based on a modular industrial computer is described as well. The metrological characteristics for different flow-meters are presented and the obtained results are discussed. It is also shown that the experience gained allows separationless flow-meter for three-phase oil-gas-formation water flows to be produced.

To measure the concentration of combustible gases, continuous operation devices based on the thermocatalytic principle have become very widespread. Studies have been carried out on the feasibility of manufacturing a fire and explosion protection device of such a device from a composite material instead of the nickel powder currently used. The porosity of the material and its effect on the strength characteristics are evaluated. A significant decrease in the complexity of manufacturing the product and its cost is shown when the indicators of strength and gas permeability are consistent.

The paper presents the results of studies of the impact of operating time of single-bucket excavators on their operational performance. The results of production experiments made it possible to establish the dependence of the pressure change in the hydraulic system of the excavator during the process of cutting soil on the operating time. This parameter characterizes the variation value of the cutting resistance of soil at the cutting edge of a bucket, the duration of operation cycle and its operational productive capacity. Based on the results of the study, a technique has been developed that permits to determine economically feasible periods of effective operation of excavators, as well as to establish the optimal technological parameters for cutting soil: the thickness of the soil shavings and speed of its cutting by an excavator.

A new version of a system to monitor the average void fraction, φ, the quality, x, and the mass flow rate, G, of two-phase liquefied natural gas (LNG) flows is offered. It is based on a combination of a gamma-densitometer with a Cs-137 radioactive source and a narrowing device. The metrological characteristics of this system are estimated and its practical realization is substantiated. A model of ID =100 mm has been manufactured and tested at the State Primary Special Standard of the Unit of Mass Flow Rate of Gas-Liquid Mixtures GET 195-2011 (Kazan, Russia) with simulated two-phase flows “Exxsol – compressed air”. The offered system can be used for pipelines up to ID =500 mm by applying a gamma source with the necessary activity. The experiments on GET 195–2011 have shown that the void fraction error and the relative mass flow rate error for Exxsol do not exceed 5% and 2%, respectively, at φ

The calibration principle of the cryogenic void fraction RF-sensors of a round cross-section for a wide temperature range is proposed and described in detail. It is shown that the simplest and reliable method of the calibration procedure requires finding a dependence of the resonant frequency, f, of the empty sensor on its temperature and only two f-values when it is filled with saturated liquid and vapor at the given temperature T0. The calibration test-bench is described. The errors of the calibration are estimated, and the experimental data for helium, hydrogen and nitrogen are presented.

To obtain a nanocrystalline structural state of materials based on aluminum and titanium, high degrees of deformation are employed: rolling with considerable reduction; and shear under high pressure (5 GPa). The nanocrystalline materials obtained are used to create thin-layer composites, with nanocrystalline silicon between the uniform layers. Measurements show that the microhardness of the composites after the application of high pressure is 2.5 (for Al–Si) and 6 (for Ti–Si) times that of the initial material, while optimal practical properties are retained. The nanocrystalline composites obtained may be recommended for ultrahard thin-layer coatings on narrow or stressed local sections of components and for local corrosion protection.

The analytical review covers the key factors that influence permeability of a coalbed under mining-induced alteration of stress state. The authors put forward an analytical relation between coal permeability, stresses and adsorbed gas to define parameters of gas leakage zone parameters and laws of mass transfer. The analytically derived relation is compared with the known model of coal structure and with the experimental results. The proposed model of coalbed permeability allows mechanism of leakage and localization of seepage zones in coal provided that the model parameters are properly selected or found experimentally.

The aim of the work is to study the kinetics of crystallization of melts with complex additives. Studies have shown that microalloying alloys with complex additives leads to a change in the structure of the melt, crystallization conditions, and the release of the main and excess phases. These changes consist of a decrease in the crystallization interval of the alloy due to an increase in the solidus temperature, an increase in the rate of growth of the solid phase in the initial period of crystallization, a replacement of the mechanism of crystallization of carbides, and an increase in the temperature at which the precipitation of eutectic and hardening phases begins.

Interest in the mathematical modeling of the carbohydrate metabolism regulation system increases in recent years. This is associated with a «closed loop» insulin pump development (it controls an insulin infusion depending on the blood glucose level). To create an algorithm for the automatic control of insulin (and other hormones) infusion using an insulin pump it is necessary to accurately predict glycaemia level. So, the primary objective of mathematical modeling is to predict the blood glucose level changes, caused by the wide range of external factors. This review discusses the main mathematical models of blood glucose level control physiological system (simplified insulin–glucose system). The two major classes of models — empirical and theoretical — are described in detail. The ideal mathematical model of carbohydrate metabolism regulatory system is absent. However, the success in the field of blood glucose level control modeling and simulating is essential for the further development of diabetes prevention and treatment technologies, and creating an artificial pancreas in particular.

Technological process of extrusion of hollow eccentric workpiece for high-pressure pump of diesel engine is investigated. Extrusion process with various sizes of eccentric head is simulated by means of QForm 2D finite element system.

The structural state and the resistance to stress-corrosion cracking (SCC) at constant loads have been studied using samples with a grown crack by the method of the cantilever bending on quenched austenitic stainless steels of the 20Cr-6Ni-11Mn-2Mo-N-V-Nb (Kh20N6G11M2AFB) type, with different contents of nitrogen (0.17, 0.34, 0.43, and 0.50 wt % N). The tests were conducted in a 3.5% aqueous solution of NaCl (without providing polarization) and in a similar solution under cathodic polarization, which causes the formation of hydrogen. It has been shown that, in a chloride solution without polarization, the steels do not undergo SCC for 2000 h. In the case of significant cathodic polarization via employment of a magnesium protector, there was revealed a brittle character of fracture upon SCC in all steels. It has been shown that steel with a nitrogen content of 0.43 wt % possesses the maximum absolute values of rupture stresses under the conditions of cathodic polarization.

Considered are the issues of the impact of the Don River runoff on the water level in the eastern part of the Taganrog Bay as well as the issues of the determination of the real depth in this part of the sea. Investigated are the cases of the wind absence and wind of western and eastern directions. Presented is the forecast of the sea level in the eastern part of the Taganrog Bay.

Thе report concerns resistive temperature sensors, their calibration system and features to mount these sensors; RF-void fraction sensors and set-up to calibrate them; a discrete level-meter based on a resistive temperature sensor; and two-phase helium flow-meters. A way to produce a multi-channel measuring system is proposed to be applied for superconducting accelerators like FAIR-SIS100 and NICA. It is also shown that the experience obtained in cryo-diagnostics allows one to produce the separation less flow-meters for the three-phase oil-salty water-gas flows which are typical in the oil production industry.

To improve the mechanical and operational properties of nickel alloys, complex modification has become widespread, in which refractory compound powders are used as inoculants. However, industrial powders are distinguished by a significant scatter of the specific surface and particle dispersion values. The aim of the work was to study the effect of the preliminary preparation of powders on their dispersity and dimensional stability. A method is proposed for preparing ultradispersed powders of plasma chemical synthesis for introduction into a liquid metal, including high-temperature purification of particles using ultrasonic vibrations of 17·103 Hz with an input power of 20 W/cm3 in the melt of alkali metal halides. It is established that the preliminary preparation of powders provides activation of particles and increases their dispersion by five times, dimensional stability by seven times, and the number of particles of nano-sized level increases to eight times.

On the basis of experimental data, operation of the conical narrowing device, which is a part of the separationless three-phase flow-meter “oil-water-gas” of ID = 100 mm, is analyzed. The component composition is determined by a spectrometric dual energy gamma densitometer in this flow-meter. With the involvement of the study of model horizontal single-phase, two-phase and three-phase flows, operation features of the narrowing device are revealed and an approach to the assessment of the main parameters of the flow meter is justified. Experimental data were obtained for more than 500 combinations of component compositions of single-phase, two-phase and three-phase flows. Most of the obtained relative errors in determining the flow rates of liquid components are within the limits recommended with Russian State Standard − GOST R 8.615-2005.

Technological process of cold forging of the plunger tappet by using backward-and-forward extrusion is developed. Manufacturing process of the blank is simulated by means of QForm 3D simulation software. Measures for removal of causes of possible defects are described.

The article presents history of becoming in Russia on standards of low regulating regimen of working time of medical personnel. The normative legal acts of the USSR and the RSFSR having juridical empower nowadays are presented.