Rapid Combustion Synthesis of Light-Storing-Emitting Material SrAl[sub 2]O[sub 4]:Eu[sup 2+],Dy[sup 3+] and Its Spectral Characteristics

2006 ◽  
Vol 153 (4) ◽  
pp. H86 ◽  
Author(s):  
Yuqi Zhang ◽  
Zhonglin Chen ◽  
Zhiming Zhou
Keyword(s):  
Combustion Synthesis ◽  
Spectral Characteristics ◽  
Rapid Combustion

scholarly journals Luminescent Properties of Al2O3:xEu obtained by Rapid Combustion Synthesis

2020 ◽  
Vol 842 ◽  
pp. 012011
Author(s):  
E. Viesca-Villanueva ◽  
D. Chavez ◽  
C. R. García ◽  
B. Esquivel ◽  
E. Martínez-Sánchez ◽  
...  
Keyword(s):  
Combustion Synthesis ◽  
Luminescent Properties ◽  
Rapid Combustion

Ultra-rapid combustion synthesis of Na2FePO4F fluorophosphate host for Li-ion and Na-ion insertion

Ionics ◽  
2017 ◽  
Vol 24 (8) ◽  
pp. 2187-2192 ◽  
Author(s):  
Lalit Sharma ◽  
Ankush Bhatia ◽  
Loïc Assaud ◽  
Sylvain Franger ◽  
Prabeer Barpanda
Keyword(s):  
Combustion Synthesis ◽  
Rapid Combustion ◽  
Li Ion ◽  
Ion Insertion

Rapid Combustion Synthesis of Metal Oxides Species Highly Dispersed on Layered Silicate Magadiite

2020 ◽  
Vol 5 (2) ◽  
pp. 569-574
Author(s):  
Xuyang Jing ◽  
Yifu Zhang ◽  
Qiushi Wang ◽  
Yan Cheng ◽  
Changgong Meng
Keyword(s):  
Metal Oxides ◽  
Combustion Synthesis ◽  
Layered Silicate ◽  
Rapid Combustion ◽  
Highly Dispersed

Rapid combustion synthesis of Cu2Y2O5 as a precursor for CuYO2 delafossite

2018 ◽  
Vol 14 ◽  
pp. 233-239 ◽  
Author(s):  
Andrei V. Racu ◽  
Radu Baies ◽  
Srinivas R. Popuri ◽  
Mihai-Cosmin Pascariu ◽  
Mircea Niculescu ◽  
...  
Keyword(s):  
Combustion Synthesis ◽  
Rapid Combustion

АКУСТИЧНА ПОМІТНІСТЬ БЕЗПІЛОТНИХ ЛІТАЛЬНИХ АПАРАТІВ З СИЛОВИМИ УСТАНОВКАМИ НА БАЗІ ПОРШНЕВИХ ДВИГУНІВ

2020 ◽  
pp. 62-80
Author(s):  
В. В. Руденко ◽  
И. В. Калужинов ◽  
Н. А. Андрущенко
Keyword(s):  
Control System ◽  
Internal Combustion Engine ◽  
Power Plants ◽  
Combustion Engine ◽  
Spectral Characteristics ◽  
Experimental Studies ◽  
Internal Combustion ◽  
Detection Range ◽  
Acoustic Signature ◽  
Static Conditions

The presence in operation of many prototypes of UAVs with propeller propellers, the use of such devices at relatively low altitudes and flight speeds makes the problem of noise reduction from UAVs urgent both from the point of view of acoustic imperceptibility and ecology.The aim of the work is to determine a set of methods that help to reduce the visibility of UAVs in the acoustic range. It is shown that the main source of noise from the UAV on the ground is the power plant, which includes the engine and the propeller. The parameters of the power plants influencing the processes that determine the acoustic signature of the UAV were investigated. A comprehensive analysis of the factors affecting visibility was carried out. The power plants include two-stroke and four-stroke engines, internal combustion and two-blade propellers. The use of silencers on the exhaust of the internal combustion engine was considered. The spectral characteristics of the acoustic fields of the propeller-driven power plants for the operating sample of the UAV "Eco" were obtained. The measurements were carried out in one-third octave and 1/48 octave frequency bands under static conditions. The venue is the KhAI airfield. Note that the propellers that were part of the power plants operated at Reynolds numbers (Re0,75<2*105), which can significantly affect its aerodynamic and acoustic characteristics. It is shown that when choosing a UAV control system, one should take into account the fact that two-stroke piston engines are the dominant source in the noise of propeller-driven control systems in the absence of a hood and mufflers in the intake and exhaust tracts. The use of a four-stroke internal combustion engine significantly reduces the noise of the control system. In the general case, the position of the boundaries of the zone of acoustic visibility of a UAV at the location of the observer is determined by the ratio between the intensity of acoustic radiation perceived by the observer from the UAV and the intensity of sound corresponding to the natural acoustic background and depends on the degree of manifestation of acoustic effects accompanying the propagation of sound in a turbulent atmosphere - the refraction of sound waves. Absorption and dissipation of acoustic energy. The calculation and comparison of the UAV detection range was carried out taking into account the existing natural maskers.The results of experimental studies are presented that allow assessing the degree of acoustic signature of the UAV. A set of measures aimed at reducing the intensity of the acoustic signature of the UAV in various regions of the radiation spectrum has been determined.

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