scholarly journals Experimental studies of vibration fields of a freight train in the far zone

2021 ◽  
Vol 2131 (5) ◽  
pp. 052051
Author(s):  
E Ya Bubnov
Keyword(s):  
Solid Medium ◽  
Experimental Studies ◽  
Wave Structure ◽  
Seismic Signal ◽  
Railway Track ◽  
Railway Transport ◽  
Frequency Range ◽  
Freight Train ◽  
Spring Suspension ◽  
Infrasonic Signal

Abstract The article analyzes the sources of radiation of seismic and acoustic signals of railway transport. To determine the wave structure of the seismic field of freight train in the experiment, a linear antenna was used, located at a distance of 1000 m from the railway track. A fine spectral analysis of the seismic signal reveals the presence of two harmonics in the frequency range 1–6 Hz. One of the dominant in amplitude discrete coincides in frequency with the harmonic of the acoustic signal, which indicates the refraction of the acoustic wave into a solid medium at the location of the seismic sensor. The source of the infrasonic signal at the specified frequency can be the resonant oscillation of the car on the spring suspension elasticity. The second discrete at a frequency of 2.7 Hz remains unchanged during the movement of various trains and is even present in microseismic noise, which indicates the imposition of a layered structure of a solid medium. The propagation velocity of this harmonic of the seismic signal is less than the velocity of sound. The totality of the marked features makes it possible to identify this wave with the surface wave formed by the layer.

ELECTRICAL IMMUNITY CHARACTERISTICS OF MULTI-PAIR LAN CABLES

2021 ◽  
Author(s):  
И.С. ШЕРСТНИКОВ ◽  
В.В. СМИРНОВА ◽  
В.Б. ПОПОВ
Keyword(s):  
Noise Immunity ◽  
Experimental Studies ◽  
Electrical Characteristics ◽  
Frequency Range ◽  
Protective Polymer

Приводятся результаты экспериментальных исследованийпомехозащищенности цепей многопарных LAN-кабелей вдиапазоне частот до 100 МГц Показано, что разработанный комплекс мероприятий по технологии скрутки кабельного сердечника, наложению на него экрана и защитной полимерной оболочки позволяет обеспечить выполнение норм на электрические характеристики помехозащищенности цепей кабеля, отвечающих требованиям категории 5е. The results of experimental studies of noise immunity of multipair LAN-cable circuits in the frequency range up to 100 MHz are presented. It is shown that the developed set of measures for the technology of twisting the cable core and applying a screen and a protective polymer sheath on it made it possible to ensure compliance with the standards for the electrical characteristics of noise immunity of cable circuits that meet the requirements of category 5e.

scholarly journals STUDY OF PROCESSES OF PRESSURE AND IMPULSE FREQUENCY INFLUENCE ON PENETRATION OF LIQUIDS IN THE SAND SAMPLES

2016 ◽  
pp. 120-125
Author(s):  
M. Ya. Habibullin ◽  
R. R. Shangareyev
Keyword(s):  
Experimental Data ◽  
Oil Recovery ◽  
Pressure Fluctuations ◽  
Experimental Studies ◽  
Regression Equations ◽  
Linear Variation ◽  
Frequency Range ◽  
Impulse Frequency ◽  
Overburden Pressure

The article deals with the issues related to the hydrocarbon reservoirs oil recovery enhancement. It describes the bench laboratory experimental studies. The results obtained during determination of fluid leakage through the rock samples and the amount of absorption of pressure fluctuations at various regime parameters are presented. Using the experimental data the regression analysis was performed on the basis of which the qualitative correlations between factorial and resultant features were identified. Using the regression equations the graphic relations were constructed. It was found that with increasing the oscillation frequency of the fluid the amount of fluid passing through the sample of porous medium increased, with the highest value of q reached at the frequency range of 600 ... 1000 Hz. With increase in the oscillations penetration depth the absorption of the amplitude of the pressure fluctuations corresponds to the linear decrease, and with the overburden pressure increase the linear variation of absorption is distorted.

scholarly journals Methodology for studying impulse disturbance from rail joints to the railway vehicle and assessment of the efficiency of the new spring suspension

2018 ◽  
Vol 239 ◽  
pp. 01032
Author(s):  
Viktor Nekhaev ◽  
Viktor Nikolaev ◽  
Evgenii Cheltygmashev
Keyword(s):  
Energy Dissipation ◽  
Comparative Assessment ◽  
Railway Track ◽  
Railway Vehicle ◽  
Vertical Acceleration ◽  
External Disturbances ◽  
Spring Suspension ◽  
Dynamic Forces ◽  
Typical Scheme ◽  
Freight Car

The methodology for studying the impulse disturbance of the railway track joints on the indicators of the dynamic qualities of the railway vehicle has been developed. The dependence of the impulse repetition factor on the energy dissipation level in the system and the speed of the vehicle is obtained. A comparative assessment of the dynamic qualities of a freight car with a typical scheme of spring suspension and a car with suspension based on the principle of compensation of external disturbances is performed. It has been established that the spring suspension of a freight car based on the principle of compensation of external disturbances delivers to it significantly better indicators of dynamic qualities in comparison with car equipped with a new three-piece truck with a typical scheme of springs. Vertical acceleration of the car’s body with a new scheme of vibration protection and dynamic forces in spring suspension is several times less than for a car with a typical three-piece truck structure.

scholarly journals Theoretical and experimental studies of highly selective planar two-dimensional Bragg structures based on dielectric waveguides in the terahertz frequency range

2019 ◽  
Vol 30 ◽  
pp. 07009
Author(s):  
Naum Ginzburg ◽  
Nikolay Peskov ◽  
Vladislav Zaslavsky ◽  
Ekaterina Kocharovskaya ◽  
Andrey Malkin ◽  
...  
Keyword(s):  
Bragg Reflection ◽  
Experimental Studies ◽  
Three Dimensional ◽  
Dielectric Waveguides ◽  
Two Dimensional ◽  
Terahertz Frequency ◽  
Frequency Range ◽  
Terahertz Frequency Range ◽  
Three Dimensional Modeling ◽  
Bragg Structures

Based on theoretical approach and three-dimensional modeling using the CST Microwave Studio code, planar dielectric two-dimensional Bragg structures in terahertz frequency range were developed and manufactured. Proof-of-principle electrodynamic experiments on the “cold” testing of these structures were carried out. It is shown that the experimental results are in good agreement with the theoretical predicts, including the existence of the highest Q mode inside the Bragg reflection band in the absence of periodicity defects.

scholarly journals Results of theoretical and experimental studies on determining the coefficient of subgrade reaction of sleepers for the conditions of main railways with axial loads of 30-35 tons per axle

2018 ◽  
Vol 230 ◽  
pp. 01003
Author(s):  
Oleksandr Darenskiy ◽  
Eduard Bielikov ◽  
Olexii Dudin ◽  
Alina Zvierieva ◽  
Anatolii Oleshchenko
Keyword(s):  
Sustainable Development ◽  
Reinforced Concrete ◽  
Axial Load ◽  
Experimental Studies ◽  
Operating Conditions ◽  
Railway Track ◽  
Rolling Stock ◽  
Subgrade Reaction ◽  
Axial Loads ◽  
Interaction Dynamics

The article considers obtaining numerical values of the coefficient of subgrade reaction of wooden and reinforced concrete sleepers with axial loads up to 30-35 tons per axle. It has been concluded that using the rolling stock with axial loads of up to 35 tons per axle is necessary in order to ensure sustainable development of the railway complex. The performance of the railway track thus should be investigated in order to predict its operation in such conditions. Generally, such studies are performed using numerical methods. One of the parameters that are required for such calculations is the parameter which is commonly called the coefficient of subgrade reaction. Empirical dependencies of the coefficient of subgrade reaction of wooden and reinforced concrete sleepers on the axial load and on the operating conditions of the track have been obtained. The obtained results can be used in studies of the interaction dynamics of the track of main railways with rolling stock with axial loads of 30-35 tons per axle, which will give an opportunity to provide well-grounded recommendations on the rules for the arrangement and maintenance of the track in such conditions.

scholarly journals IDENTIFICATION OF NORMAL WAVES FORMING A SOUND FIELD IN A SHALLOW SEA AT THE INFRASONIC FREQUENCY RANGE. Part II

2020 ◽  
Author(s):  
С.Б. Касаткин
Keyword(s):  
Experimental Studies ◽  
Sound Field ◽  
Noise Signal ◽  
Energy Structure ◽  
Frequency Range ◽  
Field Zone ◽  
Normal Waves ◽  
Infrasonic Frequency ◽  
Scholte Waves ◽  
Scholte Wave

Анализируются результаты экспериментальных исследований звукового поля, зарегистрированного комбинированными приемниками, образующими вертикально ориентированную двухэлементную антенну. Звуковое поле формировалось дискретными составляющими вально-лопастного звукоряда шумового сигнала НИС «Юрий Молоков» в инфразвуковом диапазоне частот 2–20 Гц, а также буксируемым низкочастотным излучателем полигармонического сигнала в диапазоне частот 30–60 Гц. Глубина моря и рабочий диапазон частот 2–20 Гц исключали возможность возбуждения нормальных волн дискретного спектра в модельном волноводе Пекериса в этом диапазоне частот. По результатам спектрального анализа шумового сигнала получена оценка потенциальной помехоустойчивости комбинированного приемника при использовании полного набора информативных параметров, характеризующих энергетическую структуру звукового поля. По результатам анализа вертикальной структуры звукового поля в инфразвуковом диапазоне частот был сделан вывод о том, что звуковое поле сформировано неоднородными нормальными волнами Шолте, регулярной и обобщенной (гибридной). В дальней зоне источника доминирует регулярная волна Шолте, локализованная на границы раздела вода – морское дно. В ближней зоне источника возрастает роль обобщенной волны Шолте, локализованной на горизонте источника, а звуковое поле формируется парой волн Шолте, регулярной и обобщенной. The results of experimental studies of the sound field recorded by combined receivers forming a vertically oriented two-element antenna are analyzed. The sound field was formed by discrete components of the vane-blade scale of the noise signal of the science ship «Yuri Molokov» in the infrasonic frequency range of 2–20 Hz, as well as by a towed low-frequency emitter of a polyharmonic signal in the frequency range 30–60 Hz. The depth of the sea and the operating frequency range of 2–20 Hz excluded the possibility of exciting normal waves of the discrete spectrum in the model Pekeris waveguide in this frequency range. Based on the results of spectral analysis of the noise signal, an estimate of the potential noise immunity of the combined receiver was obtained using a full set of informative parameters characterizing the energy structure of the sound field. Based on the results of the analysis of the vertical structure of the sound field in the infrasonic frequency range, it was concluded that the sound field is formed by inhomogeneous normal Scholte waves, regular and generalized (hybrid). In the far zone of the source, a regular Scholte wave dominates, localized at the water – seabed interface. In the near-field zone of the source, the role of the generalized Scholte wave localized at the source horizon increases, and the sound field is formed by a pair of Scholte waves, regular and generalized.

scholarly journals BRAKING EFFICIENCY OF QUARRY TRAINS WITH SIX-BOGIES DUMP CARS OF THE INCREASED AXIAL LOAD UP TO 27.7 TF

2021 ◽  
pp. 111-126
Author(s):  
Oleksandr Safronov ◽  
◽  
Yurii Vodiannikov ◽  
Pavlo Khozia ◽  
Anton Mozheiko
Keyword(s):  
Axial Load ◽  
Railway Track ◽  
Opencast Mining ◽  
Railway Transport ◽  
Maximum Slope ◽  
Industrial Enterprises ◽  
Study Results ◽  
Dump Trucks ◽  
Braking Distance ◽  
Traction Unit

Improving the technical level of railway transport of industrial enterprises is expressed in the introduction of advanced types of traction (locomotives and electric locomotives), four and six-axle specialized cars, including self-unloading, automation and telemechanics. To increase the productivity of quarry trains at PJSC "Kryukiv Railway Car Building Plant" a six-axle dump car model 33-7141 for quarry railway transport was designed. The car is designed for transportation from quarries of open cut hard rocks, ore and other bulk and lump cargo with density (1.75-4.0) t/m3, as well as mechanized unloading on dumping sites or crushing units of opencast mining. A distinctive feature of innovative dump cars from typical ones is the increase of cargo weight by 10 t and axial load to 271.6 (27.7) kN (ts). In this regard, the issues of assessing the braking efficiency of a quarry train with innovative dump cars that meet the requirements for railway industrial transport are becoming relevant. The article presents the study results of the braking efficiency of a quarry train composition of 10 and 14 cars. Locomotive TEM7 and unit OPE1AM with one and two motor cars were considered as traction units. The maximum permissible speeds were determined in a given range of slopes of the railway track, and the maximum possible descent was set provided that the braking distance does not exceed or will be equal to 300. As a result of research, it was found that the maximum allowable deviations ranged from 34 ‰ to 38 ‰ depending on the number of cars and traction units. The speed of trains with innovative dump trucks on the site is 42 km/h. Key words: dump car, tipping wagon, maximum slope, permissible speed, braking distance, traction unit.

scholarly journals COMPACT FLUORESCENT LAMPS AS SOURCES OF ELECTROMAGNETIC FIELDS OF RADIO- FREQUENCY RANGE (EXPERIMENTAL STUDY)

2019 ◽  
pp. 59-62
Author(s):  
V.N. Nikitina ◽  
G.G. Lyashko ◽  
N.I. Kalinina ◽  
E.N. Pankina
Keyword(s):  
Experimental Study ◽  
Radio Frequency ◽  
Electromagnetic Fields ◽  
Electric Fields ◽  
Experimental Studies ◽  
Frequency Range ◽  
Electronic Ballast ◽  
Fluorescent Lamps ◽  
Compact Fluorescent Lamps ◽  
Surrounding Space

The objects of this study are compact fluorescent lamps with an electronic ballast and the hygienic assessment of electromagnetic fields created by compact fluorescent lamps. As part of the work, the selection of samples of compact fluorescent lamps for the experimental study of electromagnetic fields was carried out. The background levels of electric and magnetic fields with a frequency of 50 Hz and high-frequency range were measured. Experimental studies of the spectrum and intensity of electromagnetic fields created by compact fluorescent lamps were carried out with different variants of lamp placement (in a cartridge without a light armature, in a local lighting fixture, in general lighting fixtures – chandeliers). The study showed that compact fluorescent lamps equipped with electronic ballast create electromagnetic fields of radio frequency range in the surrounding space. The main frequency of radiation in the examined lamp samples ranged from 32 to 58 kHz. The intensity of electric fields created by compact fluorescent lamps may exceed the permissible level set for consumer goods.

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