scholarly journals Formation of high-power, high-voltage rectangular pulses with the controlled stabilization of the pulse peak

2017 ◽  
Vol 35 (1) ◽  
pp. 154-158
Author(s):  
A.V. Petrov ◽  
S.K. Pavlov ◽  
Y.P. Usov
Keyword(s):  
Abrupt Change ◽  
Electrical Circuit ◽  
Storage Device ◽  
Resistive Load ◽  
Pulse Shaper ◽  
Short Term ◽  
Pulse Peak ◽  
Active Switch ◽  
Analytical Expressions

AbstractThe pulse shaper based on a capacitive storage device with an active switch operating on a resistive load is considered. The electrical circuit includes a capacitor with a reference voltage for the stabilization of peak of the pulse. The capacitor connected in parallel with a load via the unilateral conductive switch. A general analysis of the shaping circuit was carried out. Analytical expressions for determination of the stabilization accuracy and the stabilization duration have been obtained. The results of computer simulation of dependence of these characteristics as function of pulse parameters and shaper features are presented. The influence of short-term and abrupt change of the resistance load on the stabilization process of peak of the pulse is considered. The possibility of obtaining of pulses with a controlled stability of pulse peaks <1% for pulses with duration to 100 µs at voltages up to 20 kV and energy stored in a capacitor to 3.4 kJ is shown in prototype of the shaper.

Determination of allostatic load dynamics in the assessment of adaptation in temporary workers in the Arctic

2020 ◽  
pp. 547-548
Author(s):  
O. Yu. Atkov ◽  
S. G. Gorokhova
Keyword(s):  
Body Mass Index ◽  
Glucose Level ◽  
Shift Work ◽  
Allostatic Load ◽  
The Arctic ◽  
Temporary Workers ◽  
Short Term ◽  
Short Term Adaptation ◽  
The Individual

The individual dynamics of the allostatic load index was revealed mainly due to changes in the glucose level, body mass index, which makes it applicable for assessing the short-term adaptation to the stay in the conditions of shift work

Mathematical views of the fractional Chua's electrical circuit described by the Caputo-Liouville derivative

2021 ◽  
Vol 67 (1 Jan-Feb) ◽  
pp. 91
Author(s):  
N. Sene
Keyword(s):  
Caputo Derivative ◽  
Local Stability ◽  
Numerical Scheme ◽  
Equilibrium Points ◽  
Electrical Circuit ◽  
Maximal Lyapunov Exponent ◽  
Electrical Circuits ◽  
Adaptive Controls ◽  
Liouville Derivative

This paper revisits Chua's electrical circuit in the context of the Caputo derivative. We introduce the Caputo derivative into the modeling of the electrical circuit. The solutions of the new model are proposed using numerical discretizations. The discretizations use the numerical scheme of the Riemann-Liouville integral. We have determined the equilibrium points and study their local stability. The existence of the chaotic behaviors with the used fractional-order has been characterized by the determination of the maximal Lyapunov exponent value. The variations of the parameters of the model into the Chua's electrical circuit have been quantified using the bifurcation concept. We also propose adaptive controls under which the master and the slave fractional Chua's electrical circuits go in the same way. The graphical representations have supported all the main results of the paper.

Diagnostics of the location of damage to tubing oil well pipes

2019 ◽  
Vol 5 (4) ◽  
pp. 115-128
Author(s):  
Timur A. Ishmuratov ◽  
Rif G. Sultanov ◽  
Milyausha N. Khusnutdinova
Keyword(s):  
Fluid Motion ◽  
Oil Well ◽  
General Belief ◽  
Oil Flow ◽  
Specialized Equipment ◽  
Improving Accuracy ◽  
Analytical Expressions ◽  
Technical Measures ◽  
Quick Determination

The study is devoted to the mathematical description of the process of oil outflow in places of leakage of the tubing string, which allows a computer to locate a leakage in the tubing. The authors propose methodology for identifying defects in the tubing and determining the location of the leak. The uniqueness of this methodology lies in quick determination of the place of leakage without the use of specialists, sophisticated and specialized equipment. Mathematical modeling of oil flow in the tubing requires the apparatus of continuum mechanics. It is a general belief that the movement of oil in the pipe flows at low speeds due to its outflow from the hole. Using the general equations of mass and energy balance, the authors have obtained differential equations of fluid motion in a vertical pipe in the process of its outflow from the tubing and in the process of injection. Analytical expressions are the solution to these equations, as they can help in estimating the degree of damage and its location, as well as the feasibility of its eliminating. The results show that an increase in the leakage and injection times leads to improving accuracy of locating damage. Thus, when conducting various geological and technical measures (GTM) at the well, it is possible to assess the presence of leakage and its intensity when deciding on the repair of tubing.

Determination of the Effective Depth for Double-Fiber Fluorometric Sensors

1992 ◽  
Vol 46 (6) ◽  
pp. 919-924 ◽  
Author(s):  
Zhong Yuan Zhu ◽  
M. Cecilia Yappert
Keyword(s):  
Fiber Optic Sensor ◽  
Fluorescence Signal ◽  
Acceptance Angle ◽  
Fiber Sensors ◽  
Sample Depth ◽  
Effective Depth ◽  
Different Diameters ◽  
Semi Empirical ◽  
Analytical Expressions

The relationship between the relative fluorescence signal excited and collected with a double-fiber optic sensor and the sample depth has been investigated. The complexity of the analytical expressions for the relative fluorescence signal and the effective depth was reduced by deriving a set of semi-empirical equations which can be evaluated in a simple fashion. These expressions take into account the configuration of the sensor, i.e., fiber diameter, acceptance angle, and separation between fibers. The expressions were tested with the use of double-fiber sensors with different diameters and separations between fibers. The reduction of the effective depth in solutions with significant absorbance was evaluated.

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