Detection of antineutrino by the reaction of the inverse
β
-decay can be used for an independent monitoring of a nuclear reactor power. DANSS detector is located directly under a commercial WWER-1000 ...reactor and counts up to 5000 antineutrino per day, providing the accuracy of 1.5% in 2 days of the flux measurement. A powerful system of the passive and active shielding in combination with the fine spatial segmentation of the detector allows to diminish the contribution of the background processes to a level, negligible in comparison to the statistical error. The influence of the nuclear fuel composition on the neutrino flux can be accounted for based on the input from the NPP staff.
Induction heating of a carburizing container using induction heating was studied. The dependency of heating up to the temperature of 1660 °C was determined depending on the current values I from 0.5 ...to 2 kA on the inductor at the frequency of 112.5±2.5 kHz. Experimental results were compared to the data of numerical simulation of heat transfer in the carburizing container.
Retrospective health analysis was performed having the data from 211 airline pilots and 168 flight mechanics with symptoms of chronic sensorineural hearing loss gathered in the period from 2015 to ...2020. There were 2 control groups. One group consisted of bus drivers comparable to pilots in terms of acoustic environment and work intensity. The other group included power station operators working in standard acoustic environments and doing intensive work. The results of research revealed statistically significant differences between pilots and control group examinees in frequency of circulatory system diseases of pilots – 22.45 – 7.08; 71.19, respiratory organs – 0.18 0.07; 0.44, digestive organs – 17.13 1.90; 154.21, musculoskeletal and connective tissue – 15.44 0.93; 254.97, nervous, urogenital system – 11.49 0.79; 167.61. In comparison with the control groups, pilots were at a higher risk of cerebral atherosclerosis 13.79 2.81; 67.58, essential hypertension 14.25 1.01; 200.78, spinal osteochondrosis 3.00 0.39; 22.95, prostate hyperplasia 2.29 0.11; 48.82 and chronic prostatitis 3.43 0.20 ; 57.65. Also stated was a statistical difference in the medium of chronic diseases at the retirement age in pilots and flight mechanics in comparison with the control members: 6.0 (4.0–8.0) pilots, 6.0 (4.5–8.0) flight mechanics, 3.0 (1.0–5.0) drivers, 2.0 (1.0–3.0) operators;
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Purpose. To substantiate the improvement of the load-bearing element of the wagon-platform for the possibility of transporting bulk cargoes. Methodology. In order to be able to transport bulk cargo ...on the wagon-platform, it is proposed to install a composite boiler module on it. In order to determine the dynamic load of the improved load-bearing structure of the wagon-platform, mathematical modeling was performed. The mathematical model formed by professor Bohomaz H.I. was used. However, within the framework of the research this model was refined to determine the load of the wagon-platform of the proposed design. The solution of the system of differential equations is carried out in the MathCad software package. To do this, the mathematical model was reduced to the normal Cauchy form, and then integrated by the Runge-Kutta method. The obtained acceleration is taken into account when calculating the strength of the advanced load-bearing structure of the wagon-platform. The calculation is performed in the SolidWorks Simulation software package, which implements the finite element method. Also, within the research the modal analysis of a load-bearing structure of the wagon-platform is carried out. Findings. Based on the calculations, it is established that the acceleration acting on the load-bearing structure of the wagon-platform car is 0.38 g, i.e. it is within acceptable limits. The results of the calculation of the strength of the improved design of the wagon-platform showed that the maximum equivalent stresses occur in the area of interaction of the spine beam frame with the pivot and is about 340 MPa, the maximum displacement made 8.6 mm. That is, the obtained stresses do not exceed the yield strength of the structural material. The results of the modal analysis showed that the values of the natural frequencies of oscillations are within acceptable limits, because the first natural frequency has a value greater than 8 Hz. Originality. The scientific substantiation of improvement of a load-bearing structure of a universal wagon-platform to transportations of bulk cargoes is carried out. Practical value. The conducted research will promote increase in efficiency of operation of railway transport and creation of developments concerning planning of innovative designs of a rolling stock.
Purpose. Creation and substantiation of the measures for adopting the supporting structure of the multipurpose semi-car to carry cargoes that need weather protection. Methodology. For the adaptation ...of supporting constructions of semi-cars to carriage of cargoes that need weather protection, it was proposed to apply a removable roof manufactured from composites. As the application of a removable roof enlarges the volume of the container of the semi-car, the authors defined the load on its construction with the help of mathematical modeling. The authors see semi-car as a system which includes three components – a supporting construction having a roof with two carts. The Runge-Kutta method was used to calculate the main dynamic parameters of the semi-car. These defined dynamic parameters were accounted during calculation of the strength of the dismountable roof. Graphic spatial modeling of a semi-car with a dismountable roof was performed in the SolidWorks software kit. The calculation of solidity is implemented by the method of ultimate elements using the SolidWorks Simulation program kit. The original frequencies and forms of vibrations of the supporting construction of the semi-car are performed in this research. Findings. The outcomes of a mathematical model of the dynamic loading of the supporting construction of the semi-car having a dismountable roof set that the obtained dynamic parameters are not higher than the allowable values. The acceleration of the semi-car supporting construction in the gravity center made approximately 4.5 m/s2. The vertical dynamic ratio amounts to 0.53. The car motion is evaluated as “excellent”. It was found that when the vertical load acts on the dismountable roof, the maximum tension emerging inside is 173.2 MPa. When concentrated load affects the dismountable roof, the biggest tensions are focused on the zones of its attachment to the upper strapping of the casing, and makes 205.7 MPa. It can be seen from the modal analysis that the first original frequency of the semi-car casing is equal to 9.6 Hz, which is more than the allowable value – 8 Hz. Originality. Models for determining the loading of the supporting construction of the semi-car having a dismountable roof from composites within the general modes of loading operation are given in this study. Practical value. The study results allow expanding the applicability of semi-cars by adapting them to the carriage of cargoes, which need protection from weather effects and can increase the performance of railroad carriage.
The conductance of channels formed by cylindrical walls and of rectangular channels in a wide range of pressures and pressure ratios was defined with the help of numerical solution of Navier–Stokes ...equations system. The mathematical model was verified. The results of the numerical solution were approximated in the form of equations which can be used in mathematical models of non-contact pumps and compressors.
•Flow through channels formed by cylindrical walls is considered.•Mass flow rate and conductance are found by numerical solution in laminar regime.•Formula for three types of channels for different dimensions and pressures is given.•Comparison of experiment and calculation verifies adequacy of obtained formula.•Formula for critical pressure ratio at the ends of rectangular channel is given.
The measurement results for power consumption and current in the inductor and heating temperature of titanium disc-shaped and cylindrical samples when treated with high frequency currents within 90 ...to 120 kHz have been presented. The influence of the current in the inductor in the range of 0.3 to 8.5 kA on the heating kinetics of disc-shaped samples within 800 °C to 1500 °C in the air has been identified. A regression model describing the temperature change depending on the power consumed by the heat treatment device as well as its duration has been built.
The paper presents the results of obtaining tantalum films with a thickness of 200- 900 nm on titanium using DC magnetron sputtering. As a result, a high-strength "Ti-base - Ta-coating" structure ...with a hardness of at least 2040±150 HV (20.01±1.47 GPa) was produced. The subsequent modification with high-frequency currents provided an increase in hardness to 3694±443 HV (36.23±4.35 GPa), which was associated with the formation of a thin oxide layer of TaOx with a tantalum concentration of 74.1-75.2 wt.% and oxygen of about 12.5- 13.9 wt.%.
A different approach to the typing of the section of the Bazhenov Formation is presented – the identification of the reference section of the Bazhenov high-carbon formation (BHCF). Six packs were ...distinguished according to lithological and paleontological features, and their general characteristics were given. Also, indicators of the formation conditions are described, that allow to reconstruct the history and evolution of the basin, e. g. tuff and bone-bed horizons, alginate-rich layers, radiolarite layers, spicular limestones and limestones with a «con-in-con» texture, intensely pyritized layers, packs with an abundance of bivalves. Two types of sedimentation models are formed and described: island and intra-basin upland. On the basis of new data and identified features of the paleogeography of the Bazhenov Sea, a general model of the formation of BHCF deposits in the development zone of the Bazhenov and Tutleim formations is proposed.
Current paper represents the results of viscosity and density measurements of vacuum oils for diffusion vacuum pumps. Vacuum oil samples are represented by the following brands: VM-1S, LEYBONOL LVO ...500 and Alcarin-D24. All the measurements have been carried out at atmospheric pressure: viscosity has been measured by the capillary method in the temperature range from 293 K to 373 K, and density has been measured by the pycnometer and hydrostatic weighing methods in the temperature range from 293 K to 473 K.
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