scholarly journals Measuring of plasma’s velocity in electrodynamic railgun using high-frequency method

2018 ◽  
Vol 226 ◽  
pp. 04004
Author(s):  
Vladimir V. Kirievskiy ◽  
Evgeny V. Kirievskiy
Keyword(s):  
Resonance Frequency ◽  
High Frequency ◽  
Measuring Method ◽  
Instantaneous Velocity ◽  
Frequency Method ◽  
Safety Level ◽  
Current Time ◽  
Measuring Devices ◽  
Moving Plasma ◽  
Velocity Measuring

A method is proposed for measuring the velocity of a moving plasma in an electrodynamic railgun in the part of internal ballistics. The achieved result is to provide a measurement of instantaneous velocity and an increase of the safety level for operation of measuring devices. The method is based on the excitation of the rail system of railgun high frequency electric oscillations during in due motion of plasma and creates current resonance. Then is continuously measured cyclic resonance frequency, and the instantaneous velocity of the plasma is determined by a formula, that consist of the current time, the cyclic resonance frequency, equivalent inductance of the power supply of railgun, linear inductance and rail length, and as well used as a model of measurement measure capacitance of capacitor, connected in parallel to rail of railgun grounded from one side. Application of plasma velocity measuring method is suitable for the highly-accurate control of plasma acceleration and pushed it to the railgun bodies with controlled acceleration, requiring measurement during movement of the plasma instantaneous values of velocity.

Investigating Fatigue Strength of Vacuum Carburized 17CrNi6-6 Steel Using a Resonance High Frequency Method

2014 ◽  
Vol 225 ◽  
pp. 45-52 ◽  
Author(s):  
Piotr Kula ◽  
Konrad Dybowski ◽  
Sebastian Lipa ◽  
Robert Pietrasik ◽  
Radomir Atraszkiewicz ◽  
...  
Keyword(s):  
High Pressure ◽  
Fatigue Strength ◽  
High Frequency ◽  
Vacuum Carburizing ◽  
Frequency Method ◽  
Single Degree Of Freedom ◽  
Bending Fatigue ◽  
Single Degree ◽  
Bending Fatigue Strength ◽  
Frequency Changes

The bending fatigue strength of 17CrNi6-6 steel subjected to vacuum carburizing with high pressure gas hardening has been measured using a novel high-frequency technique. The test records the changes in resonance and consists of observing resonance frequency changes in a vibrating system with a single degree of freedom as a result of the forming of a fatigue crack. Moreover, a mechanism of fatigue nucleation and propagation in steel hardened by vacuum carburizing is presented.

Non-cooperative maritime target position and velocity measuring method based on monocular trajectory intersection for video satellite

2017 ◽  
Vol 233 (1) ◽  
pp. 44-56 ◽  
Author(s):  
Shengyi Chen ◽  
Haibo Liu ◽  
Xiaochun Liu ◽  
Qifeng Yu
Keyword(s):  
Target Position ◽  
Measuring Method ◽  
Observation Time ◽  
Measuring Error ◽  
Target Movement ◽  
Practical Applications ◽  
High Measurement ◽  
Velocity Measuring ◽  
Elevation Model ◽  
Intersection Method

This paper presents a passive measuring method based on monocular trajectory intersection, aimed at realizing the position and velocity measurement of a non-cooperative maritime target for video satellite. Due to the fact that the target’s moving range is relatively small in comparison to that of the satellite during the observation time, a large measuring error results when directly using the monocular trajectory intersection method for 3D motion measurement. Therefore, the dynamic sea surface elevation model is employed to increase the maritime target movement constraints, which simplifies the 3D spatial motion of the target to 2D surface motion. By combining the surface constraint and monocular trajectory intersection method, measurement robustness for a non-cooperative maritime target can be greatly improved. Furthermore, a line-surface intersection method is proposed to obtain the initial solution for motion parameters, which increases the nonlinear optimization efficiency. Simulation experiments are conducted to analyze the effect of different error factors on position and velocity accuracy. The results indicate that the proposed method achieves high measurement accuracy and is feasible in practical applications for video satellite.

scholarly journals Validation of Velocity Measuring Devices in Velocity Based Strength Training

2021 ◽  
Vol 20 (1) ◽  
pp. 106-118
Author(s):  
Thorben Menrad ◽  
Jürgen Edelmann-Nusser
Keyword(s):  
Linear Regression ◽  
Strength Training ◽  
Mean Value ◽  
Coefficient Of Determination ◽  
Regression Analyses ◽  
Measuring Devices ◽  
Strength Exercises ◽  
Measurement Units ◽  
Velocity Measuring

Abstract To control and monitor strength training with a barbell various systems are on the consumer market. They provide the user with information regarding velocity, acceleration and trajectory of the barbell. Some systems additionally calculate the 1-repetition-maximum (1RM) of exercises and use it to suggest individual intensities for future training. Three systems were tested: GymAware, PUSH Band 2.0 and Vmaxpro. The GymAware system bases on linear position transducers, PUSH Band 2.0 and Vmaxpro base on inertial measurement units. The aim of this paper was to determine the accuracy of the three systems with regard to the determination of the average velocity of each repetition of three barbell strength exercises (squat, barbell rowing, deadlift). The velocity data of the three systems were compared to a Vicon system using linear regression analyses and Bland-Altman-diagrams. In the linear regression analyses the smallest coefficient of determination (R2.) in each exercise can be observed for PUSH Band 2.0. In the Bland-Altman diagrams the mean value of the differences in the average velocities is near zero for all systems and all exercises. PUSH Band 2.0 has the largest differences between the Limits of Agreement. For GymAware and Vmaxpro these differences are comparable.

scholarly journals Structural drilling using the high-frequency (sonic) rotary method

2017 ◽  
Vol 64 (1) ◽  
pp. 1-10 ◽  
Author(s):  
Jurij Šporin ◽  
Željko Vukelić
Keyword(s):  
High Frequency ◽  
Final Part ◽  
Frequency Method ◽  
High Quality ◽  
Core Drilling ◽  
Drilling Method ◽  
Highly Effective ◽  
Theoretical Foundations

AbstractIn Slovenia, there is widespread use of structural drilling along with classical core drilling. Recently, however, the need has arisen for a highly effective core drilling method with the aid of which high-quality core might be obtained. In order to achieve this aim, one among several Slovenian companies dealing with geological surveying has decided to implement structural drilling using a high-frequency drilling method. The following article presents the theoretical foundations for such a high-frequency method, as well as the manner of its implementation. In the final part of the article, a practical comparison between the conventional and the high-frequency core drilling methods is also provided.

Rapid determination of water in benzoyl peroxide by high frequency method

1973 ◽  
Vol 22 (11) ◽  
pp. 1440-1445
Author(s):  
Yuichi KAMURA ◽  
Sabro MIZUTANI ◽  
Keiko TOMIHISA ◽  
Masakazu SUGIYAMA
Keyword(s):  
Benzoyl Peroxide ◽  
High Frequency ◽  
Rapid Determination ◽  
Frequency Method

scholarly journals The high-frequency method for scattering from the wedges of complex conductive targets in half space

2009 ◽  
Vol 58 (2) ◽  
pp. 908
Author(s):  
Li Xiao-Feng ◽  
Xie Yong-Jun ◽  
Fan Jun ◽  
Wang Yuan-Yuan
Keyword(s):  
Half Space ◽  
High Frequency ◽  
Frequency Method
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