Effect of charged sand/dust particles on signal of electromagnetic wave

Author(s):  
J. Yan ◽  
L. Xie
2010 ◽  
Vol 49 (35) ◽  
pp. 6756 ◽  
Author(s):  
Xie Li ◽  
Li Xingcai ◽  
Zheng Xiaojing

2014 ◽  
Vol 52 (3) ◽  
pp. 244-249 ◽  
Author(s):  
Yoshimi Kobayashi ◽  
Akinori Shimada ◽  
Mai Nemoto ◽  
Takehito Morita ◽  
Altanchimeg Adilbish ◽  
...  

2019 ◽  
Vol 2019 ◽  
pp. 1-11
Author(s):  
Minghua Cao ◽  
Huiqin Wang ◽  
Yu Yao ◽  
Shanglin Hou

Sand-dust weather conditions are considered the primary challenge to free-space optical (FSO) communications. It may cause severe attenuation that is malignant to FSO link performance. This study investigates the impact of sand-dust particles on a laser signal using the radiation propagation method and the small-angle approximation method. Numerical simulation shows that in sand-dust weather conditions, the multiple scattering effect is dominant and results in signal pulse delay and pulse broadening. Furthermore, the signal attenuation follows a negative exponential distribution to the laser wavelength. Superior performance can be achieved by employing a longer wavelength laser to reduce pulse delay and mutual interference.


2008 ◽  
Vol 37 (2) ◽  
pp. 151-155 ◽  
Author(s):  
S. Matsuyama ◽  
K. Ishii ◽  
H. Yamazaki ◽  
Y. Kikuchi ◽  
Y. Kawamura ◽  
...  

2014 ◽  
Vol 543-547 ◽  
pp. 400-404
Author(s):  
Hong Wei Li ◽  
Hong Yan Li ◽  
Ying Dong ◽  
Hai Bo Han ◽  
Li Niu

The velocity and concentration of sand/dust particles contained in the air flow are the key factors which affect the quality of sand/dust test. In order to obtain the anticipated sand/dust concentration and uniformity in the test segment, numerical simulation methods are adopted to study the characters of different sand/dust inject approaches. Research results indicated that the gravity sand/dust inject approach is not suitable for the large sand/dust test system, upstream spray approach is appropriate to be adopted in dust test, the uniformity of upstream sand spray method is better than downstream sand spray approach, but its diffusivity is not as good as the latter. In a certain range, the velocity difference between sand/dust spray flow and air flow affects the concentration distribution uniformity slightly. The numerical simulation results applied in the optimal design of particles inject system in some large sand/dust test system get a favorable progress. All results provide reference for the design of similar system and sand/dust environment test.


Author(s):  
Masanari Watanabe ◽  
Hisashi Noma ◽  
Jun Kurai ◽  
Kazuhiro Kato ◽  
Hiroyuki Sano

The effect of ambient air pollutants and Asian dust (AD) on absence from school due to sickness has not been well researched. By conducting a case-crossover study, this study investigated the influence of ambient air pollutants and desert sand dust particles from East Asia on absence from school due to sickness. From November 2016 to July 2018, the daily cases of absence due to sickness were recorded in five elementary schools in Matsue, Japan. During the study period, a total of 16,915 absence cases were recorded, which included 4865 fever cases and 2458 cough cases. The relative risk of overall absence in a 10-μg/m3 increment of PM2.5 and a 0.1-km−1 of desert sand dust particles from East Asia were found with 1.28 (95%CI: 1.15–1.42) and 2.15 (1.04–4.45) at lag0, respectively. The significant influence of PM2.5 persisted at lag5 and that of desert sand dust particles at lag2. NO2 had statistically significant effects at lag2, lag3, and lag4. However, there was no evidence of a positive association of Ox and SO2 with absence from school. These results suggested that PM2.5, NO2, and AD increased the risk of absence due to sickness in schoolchildren.


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