Piezoelectric Actuators Used for Helicopter Vibration Reduction

2013 ◽  
Vol 718-720 ◽  
pp. 1729-1733
Author(s):  
Zhu Zhang ◽  
Wei Dong Yang ◽  
Da Lin Yang

This paper covers the development of two piezoelectric actuators for trailing edge flap control on mach scaled model helicopter rotors. The design, analysis and bench tests of these two actuators are described. Under different voltages and frequencies, their drive performances are tested and compared. Results showed that these two actuators all can effectively drive and control the flaps with each advantages and disadvantages.

2015 ◽  
Vol 19 (95) ◽  
pp. 50-53
Author(s):  
Aleksej A. Kravcov ◽  
◽  
Leonid G. Limonov ◽  
Valerij V. Sinelnikov ◽  
Stanislav V. Potapov

Author(s):  
Zenoviy Siryk

Ukraine is a unitary state, yet historically various regions, oblasts, districts, and local areas have different levels of economic development. To secure sustainable economic and social development and provide social services guaranteed by the state for each citizen according to the Constitution, the mechanism of redistribution between revenues and expenditures of oblasts, regions, and territories through the budgets of a higher level is used. The paper aims to research the peculiarities of improving interbudgetary relations in conditions of authorities’ decentralization. The paper defines the nature of interbudgetary relations. The basic and reverse subsidies to Ukraine and Lvivska oblast are analyzed. The advantages and disadvantages the communities face at changing approaches to balancing local budgets are determined. Regulative documents that cover the interbudgetary relations in Ukraine are analyzed. Special attention is paid to the problem of local finances reforming, including the development of interbudgetary relations. The scheme of the economic interbudgetary relations system in Ukraine is developed. The ways to improve the system of interbudgetary relations in Ukraine are suggested. The negative and positive aspects, advantages, and disadvantages of the system of interbudgetary relations in Ukraine require the following improvements. 1. It is necessary to avoid the complete budget alignment in the process of budgets balancing by interbudgetary transfers as the major objective. 2. The interbudgetary transfers should be distributed based on a formal approach. 3. The changes have to be introduced to the calculation of medical and educational subsidies in terms of financial standard of budget provision to avoid the money deficit for coverage of necessary expenditures. 4. There is a need to improve interbudgetary relations at the levels of districts, villages, towns, and cities of district subordination. 5. Improvement of the mechanism of targeted benefits provision, their real evaluation, and control for the use of funds.


2019 ◽  
Author(s):  
Tomasz Krzyzynski ◽  
Igor Maciejewski ◽  
Lutz Meyer ◽  
Henning Meyer

2018 ◽  
Vol 10 (6) ◽  
pp. 063304 ◽  
Author(s):  
Wenguang Zhang ◽  
Yifeng Wang ◽  
Ruijie Liu ◽  
Haipeng Liu ◽  
Xu Zhang

Plants ◽  
2021 ◽  
Vol 10 (11) ◽  
pp. 2424
Author(s):  
Aleksandr V. Ivanov ◽  
Irina V. Safenkova ◽  
Anatoly V. Zherdev ◽  
Boris B. Dzantiev

Rapid, sensitive, and timely diagnostics are essential for protecting plants from pathogens. Commonly, PCR techniques are used in laboratories for highly sensitive detection of DNA/RNA from viral, viroid, bacterial, and fungal pathogens of plants. However, using PCR-based methods for in-field diagnostics is a challenge and sometimes nearly impossible. With the advent of isothermal amplification methods, which provide amplification of nucleic acids at a certain temperature and do not require thermocyclic equipment, going beyond the laboratory has become a reality for molecular diagnostics. The amplification stage ceases to be limited by time and instruments. Challenges to solve involve finding suitable approaches for rapid and user-friendly plant preparation and detection of amplicons after amplification. Here, we summarize approaches for in-field diagnostics of phytopathogens based on different types of isothermal amplification and discuss their advantages and disadvantages. In this review, we consider a combination of isothermal amplification methods with extraction and detection methods compatible with in-field phytodiagnostics. Molecular diagnostics in out-of-lab conditions are of particular importance for protecting against viral, bacterial, and fungal phytopathogens in order to quickly prevent and control the spread of disease. We believe that the development of rapid, sensitive, and equipment-free nucleic acid detection methods is the future of phytodiagnostics, and its benefits are already visible.


Energies ◽  
2021 ◽  
Vol 14 (16) ◽  
pp. 4930
Author(s):  
Francisco Elvis Carvalho Souza ◽  
Werbet Silva ◽  
Andrés Ortiz Salazar ◽  
José Paiva ◽  
Diego Moura ◽  
...  

In order to reduce the costs of implementing the radial position control system of a three-phase bearingless machine with split winding, this article proposes a driving method that uses only two phases of the system instead of the three-phase traditional one. It reduces from six to four the number of inverter legs, drivers, sensors, and current controllers necessary to drive and control the system. To justify the proposal, this new power and control configuration was applied to a 250 W machine controlled by a digital signal processor (DSP). The results obtained demonstrated that it is possible to carry out the radial position control through two phases, without loss of performance in relation to the conventional three-phase drive and control system.


Author(s):  
Trong-Thang Nguyen

<p>In this study, the author analyzes the advantages and disadvantages of multi-level inverter compared to the traditional two-level inverter and then chose the suitable inverter. Specifically, the author analyzes and designs the three-level inverter, including the power circuit design and control circuit design. All designs are verified through the numerical simulation on Matlab. The results show that even though the three-level inverter has a low number of switches (only 12 switches), but the quality is very good: the total harmonic distortion is small; the output voltage always follows the reference voltage.</p>


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