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Author(s):  
P. Tkachyck ◽  
O. Kotcemyr ◽  
S. Sokolovskyi ◽  
D. Bilous

The article is dedicated to the the problem of not considering the real meteorological conditions in planning the flight task of the unmanned aerial vehicle (UAV) A1-CM Furia . Unmanned aerial system(UAS) A1-CM  Furia  has been developed and manufactured by LLC SPC Athlon Avia since 2014. Within 2019-2020, the UAS passed a full spectrum of state tests and was adopted by the Armed Forces of Ukraine. The main criteria that this UAS meets are the detection and tracking of enemy objectives, equipment maintenance and target  reconnaissance. Among the peculiarities of UAV application are  performance of tasks in adverse meteorological conditions, the use of radio-electronic suppression by the opposing parties, significant spatial characteristics of the areas of responsibility of units and subdivisions for reconnaissance and engagement. The change in the charge current of the battery depending on the air temperature and the change in the charge current of the battery depending on the wind speed in different meteorological conditions were analyzed  in the article. The article presents experimental results that determine the order of current consumption for battery time depending on meteorological factors, such as wind speed and air temperature. These results indicate that the UAV A1-CM Furia during the task accomplishment  can not meet the flight characteristics that are defined in the flight operation manual UAS (FAM). The FAM does not separate the differences in the use of UAV  in different meteorological conditions. This causes possible errors in calculating the maximum length of the route and the maximum possible time in the air.  In the article it was proposed to develop a correction  for the use of UAV depending on changes in wind speed and temperature . During the assessing of possible corrections for the use of UAV at different wind speeds and air temperatures, the accuracy of determining the possible values of the maximum route length and maximum time of UAV in the air allows us to calculate more accurate data for future tasks accomplisment. Experimental methods of calculating corrections took a large part in the specific study of information without taking into account the real meteorological conditions while planning the flight task of the UAV A1-CM Furia. The obtained results show that without further consideration of meteorological conditions while planning a flight task there may be inaccuracies.


2021 ◽  
Vol 12 (3) ◽  
pp. 163
Author(s):  
Ratna Aisuwarya ◽  
Ibrahim Saputra ◽  
Dodon Yendri

The need for unmanned vehicles is increasingly needed in certain conditions, such as distribution of disaster supply, distribution of medicines, distribution of vaccines in the affected areas in pandemic situations. The various types of goods to be distributed require a different fulcrum. This research implemented PID control for the quadcopter balance control system to achieve stability during hovering. PID control is used to achieve a certain setpoint to produce the required PWM output for the propeller to reach a speed that can fly the quadcopter tilted until it reaches a steady state. Tests were carried out on the roll and pitch motion of the quadcopter by providing a load. The results show that PID control can be implemented for the quadcopter balance control system during hovering by determining the PID constants for each roll and pitch motion with the constanta of Kp = 0.15, Kd = 0.108, and Ki = 0.05. The quadcopter takes 3 – 6 seconds to return to the 0 degree setpoint when it is loaded.


Lubricants ◽  
2021 ◽  
Vol 9 (11) ◽  
pp. 107
Author(s):  
Adolfo Senatore ◽  
Haiping Hong ◽  
Veronica D’Urso ◽  
Hammad Younes

The tribological behavior of novel 7.5 wt% carbon nanotube-based lubricant greases in PAO (polyalphaolefin) oil with and without 1.0 wt% MoS2, together with several other commercial greases such as calcium, lithium, were studied. The test results showed a marked reduction of frictional coefficient achieved by the CNTs based grease samples with an average benefit of around 30% compared to conventional greases. The steady state test under 1.00 GPa average contact pressure in a mixed lubrication regime and the fretting test showed the best results in terms of friction reduction obtained by CNTs greases. Steady state tests at higher average contact pressure of 1.67 GPa proved to have a lower friction coefficient for CNTs grease containing MoS2; otherwise CNTs grease without MoS2 showed an average value of CoF comparable to calcium and lithium greases, both in a boundary and a mixed regime. The protection against wear, a considerable decrease (−60%) of reference parameter was measured with CNTs grease with MoS2 (NLGI 2) in comparison with the worst conventional grease and −22% in comparison with the best conventional grease. The data indicated that our novel carbon nanotube greases show superior tribological properties and will have promising applications in the corresponding industry.


2021 ◽  
Vol 167 ◽  
pp. 108214
Author(s):  
Ahmed Sharhan ◽  
Weiyong Wang ◽  
Xiang Li ◽  
Hisham Al-azzani

2021 ◽  
Vol 11 (9) ◽  
pp. 902
Author(s):  
Cristina L. Saratxaga ◽  
Iratxe Moya ◽  
Artzai Picón ◽  
Marina Acosta ◽  
Aitor Moreno-Fernandez-de-Leceta ◽  
...  

Background: Alzheimer’s is a degenerative dementing disorder that starts with a mild memory impairment and progresses to a total loss of mental and physical faculties. The sooner the diagnosis is made, the better for the patient, as preventive actions and treatment can be started. Although tests such as the Mini-Mental State Tests Examination are usually used for early identification, diagnosis relies on magnetic resonance imaging (MRI) brain analysis. Methods: Public initiatives such as the OASIS (Open Access Series of Imaging Studies) collection provide neuroimaging datasets openly available for research purposes. In this work, a new method based on deep learning and image processing techniques for MRI-based Alzheimer’s diagnosis is proposed and compared with previous literature works. Results: Our method achieves a balance accuracy (BAC) up to 0.93 for image-based automated diagnosis of the disease, and a BAC of 0.88 for the establishment of the disease stage (healthy tissue, very mild and severe stage). Conclusions: Results obtained surpassed the state-of-the-art proposals using the OASIS collection. This demonstrates that deep learning-based strategies are an effective tool for building a robust solution for Alzheimer’s-assisted diagnosis based on MRI data.


Author(s):  
Shuyan Yang ◽  
Nassim Hemmati ◽  
Thomas Russell ◽  
Abbas Zeinijahromi ◽  
Sara Borazjani ◽  
...  

2021 ◽  
Vol 25 (4) ◽  
pp. 388-393
Author(s):  
V. M. Lukomets ◽  
M. V. Trunovа ◽  
Ya. N. Demurin

Modern sunflower breeding is significantly diversified due to the different needs of agricultural production. The breeding of sunflower varieties and hybrids is carried out at V.S. Pustovoit All-Russian Research Institute of Oil Crops (VNIIMK) in all areas in demand on the market and is based on fundamental biological research. In the field of breeding for faster maturing, the following commercial cultivars were obtained: very early maturing, cv. Skormas and the three-way hybrid Achilles, early maturing cvs. Varyag and Uspekh, medium maturing cvs. Amelie, Aris and Aurus. Within the framework of breeding for immunity, eight hybrids and one variety have been produced. So at the Don experimental station (Rostov region), productive hybrids were bred, resistant to the virulent broomrape of the G race due to the presence of the Or7 gene: ‘Gorstar’, ‘Gorfild’, ‘Grant’, ‘Status’, ‘Fogor’ and the three-way hybrid Nika. On the central experimental base, the following were obtained: the mid-early hybrid Typhoon and the earlymaturing variety Platonych with resistance to common races of downy mildew and a high oil content of achenes (up to 53 %) as well as the mid-early hybrid Tayzar, which is simultaneously resistant to virulent races of broomrape and to the causative agent of downy mildew. The early maturing large-fruited sunflower variety Belochka was included in the“Russian State Register of Selection Achievements…”, and the large-fruited varieties Karavan, Konditer and Kalibr are currently undergoing state tests. The breeding use of germplasm with genes for herbicide resistance wasaccompanied by their extensive genetic study. A practical recommendation for all three alleles of the ALS gene (Imr, CLHA-Plus, Sur) was the need to create homozygous hybrids for their reliable use in appropriate production systems. For Clearfield technology, the hybrids Imidzh, Arimi and Immi have been developed; for Clearfield Plus, the hybrid Klip; and for Express Sun (or SUMO), the hybrid Surus. Klip and Surus are mid-oleic. All newly developed fertile ornamental sunflower varieties – Aurelia, Fizalia, Zhemchuzhny, Rumyanets, Agat and Mazhor – were transferred for practical use to a sterile CMS RIG basis. Thus, new achievements have been attained across the entire spectrum of modern trends in sunflower breeding.


Author(s):  
S. Borazjani ◽  
N. Hemmati ◽  
A. Behr ◽  
L. Genolet ◽  
H. Mahani ◽  
...  

Author(s):  
Barbara Schultz-Jones ◽  
Cynthia Ledbetter

This paper presents the full results from a 2008/2009 research study examining the application of a learning environment paradigm to the school library setting. The preliminary results from the examination of the Fifth Grade science classes were presented at the IASL 2009 Research Forum. We now report the process of completing our comparative examination of the relationships among student perceptions of science programs and library programs with Third (ages 8 and 9), Fourth (ages 9 and 10) and Fifth (ages 10 and 11) Grades. In addition, we extend the assessment of these relationships to a correlation with student achievement on the standardized State tests for Texas.


2021 ◽  
Vol 345 ◽  
pp. 00020
Author(s):  
Jan Lepicovsky ◽  
David Šimurda ◽  
Petr Šidlof

Long term strategic changes in power generation approaches will require more flexibility for large power generating turbines as an unavoidable consequence of the increasing share of power generated by alternative energy sources. Demanded flexibility for the power turbine output will augment undesired flow phenomena in the low-pressure turbine module, which will consequently enhance blade flutter problems of long slender blades in turbine last stages. In order to advance the understanding of blade flutter onset conditions, the Institute of Thermomechanics of the Czech Academy of Sciences instigated an advanced research program on blade flutter research in high-speed turbomachines. A new innovative test facility for Blade Forced Flutter research was designed and built in the High-Speed Laboratory of the Institute of Thermomechanics. The concept of the new test facility is based on extensive experience with an older Transonic Flutter Cascade facility operated at the NASA Glenn Research Center in Cleveland, Ohio. At present, the first phase of verification tests of the new facility is in progress. The ongoing steady-state tests are intended for exploration of a newly proposed quasi-stationary method to investigate instigating flow conditions leading to an onset of intense blade flutter. Results of some opening tests under steady flow conditions are presented in the paper. The blade drive mechanism for unsteady tests with oscillating blades has not yet been installed in the facility. The presented paper is a work-in-progress report on the ongoing research of complex blade flutter problems.


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