83 research outputs found
Self-Organization in Multimode Microwave Phonon Laser (Phaser): Experimental Observation of Spin-Phonon Cooperative Motions
An unusual nonlinear resonance was experimentally observed in a ruby phonon
laser (phaser) operating at 9 GHz with an electromagnetic pumping at 23 GHz.
The resonance is manifested by very slow cooperative self-detunings in the
microwave spectra of stimulated phonon emission when pumping is modulated at a
superlow frequency (less than 10 Hz). During the self-detuning cycle new and
new narrow phonon modes are sequentially ``fired'' on one side of the spectrum
and approximately the same number of modes are ``extinguished'' on the other
side, up to a complete generation breakdown in a certain final portion of the
frequency axis. This is usually followed by a short-time refractority, after
which the generation is fired again in the opposite (starting) portion of the
frequency axis. The entire process of such cooperative spectral motions is
repeated with high degree of regularity. The self-detuning period strongly
depends on difference between the modulation frequency and the resonance
frequency. This period is incommensurable with period of modulation. It
increases to very large values (more than 100 s) when pointed difference is
less than 0.05 Hz. The revealed phenomenon is a kind of global spin-phonon
self- organization. All microwave modes of phonon laser oscillate with the same
period, but with different, strongly determined phase shifts - as in optical
lasers with antiphase motions.Comment: LaTeX2e file (REVTeX4), 5 pages, 5 Postscript figures. Extended and
revised version of journal publication. More convenient terminology is used.
Many new bibliographic references are added, including main early theoretical
and experimental papers on microwave phonon lasers (in English and in
Russian
Monitoring System of High Voltage Dielectric Equipment
Based on the research of the main causes of dielectric elements premature aging and electrical destruction of primary dielectric elements in high voltage electrical equipment the complex method for remote monitoring of said electrical equipment has been developed. The developed mobile diagnostic device is allowing detection and periodic control of the most dangerous defects. The set of diagnostic parameters of defects was experimentally obtained by using three physical methods (electromagnetic, optical, and acoustic), and allows to inspect the origin and development of defects, and to determine residual life of dielectric elements with a sufficient degree of reliability. The researched characteristics of the kinetics of reduction in operating parameters of polymer insulators permitted the development of the detection of accelerated increase in defects under the influence of ultra-large partial discharges
Effect of partial discharges on the operating condition of high-voltage insulators
The features of the dielectric rod defects and the rod-electrod defects of polymer insulators were investigated by using the developed complex method of contactless remote diagnostics of high-voltage insulators health, which includes the initial detection of local areas with elevated electric field gradients as well as measurement of a set of partial discharges characteristics. The radiation of extra-large partial discharges was detected and partial discharges features were investigated. According to the measurement results, a diagram was constructed for the electro-physical processes that accompany the emission of extra-large partial discharges; and the reasons for their occurrence were established
A comprehensive method for remote monitoring of the high-voltage insulators
With the help of the developed two-channel method for remote control of high-voltage insulators have been studied peculiarities of characteristics of partial discharges (PD) for determining a working condition of insulators under high voltage. Therefore, they have established diagnostic principles for the allocation of faulty insulators, as well as predictive signs of the future lifetime of healthy insulators
Development of methods for the formation of operation modes of hydropower systems using machine learning
The paper describes the method for finding a compromise solution during formation of operation modes of hydropower systems (cascade of hydropower plants). The software solution “Energy system of the HPP cascade” (http://hydrocascade.com) was implemented based on the developed methodology. In the existing model, in order to improve the accuracy of forecasting the parameters of the generating equipment of hydroelectric power plants and hydraulic structures, machine learning methods were used. The new forecast model has increased the accuracy of the forecasts by an average of 3.67%
HARDWARE AND SOFTWARE ENGINE EMULATION IN THE AUTOPILOT SYSTEMS
Now a number of the leading firms work on creation of an automobile autopilot. The authors of the presented article offer to complement the system of an autopilot with the control system of the car technical condition. The developed hardware and software complex allows working with virtual mathematical model of the gas engine of the KamAZ truck and can be recustoized under different modifications of gas and diesel engines. At the same time by means of this complex there is an opportunity to reveal the latent defects of a control system and to reduce labor input of calibration procedures. The hardware and software allows testing electronic control units in standard and emergency operation modes of sensors and actuators, thereby providing compliance to the modern Russian and international requirements to control systems of cars
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