scholarly journals Grid Deformation Real-Time Measurement System of Ion Thruster Based on Videometrics

2019 ◽  
Vol 9 (9) ◽  
pp. 1759
Author(s):  
Jiehong Yuan ◽  
Peng Dai ◽  
Dong Liang ◽  
Shiming Zhou ◽  
Shijie Xiao ◽  
...  

In order to conduct high-precision measurement of the LIPS-300 ion thruster grid deformation in a vacuum, high-temperature, and plasma environment, a noncontact videometrics system using a telemicroscope was designed. Based on the captured image, the interactive partitioning edge detection method (IPEDM) was used to obtain stable and clear edges of multiple circular cooperative targets. Meanwhile, magnification factor calibration, rotation angle correction, and subpixel-level grid deformation measurement were performed with cooperative targets. The measurement results show that under the power of 750 W in the discharge chamber, the maximum thermal deformation of the screen grid is 1120 μm, and the gap between the screen grid and the accelerator grid is reduced by 420 μm. An accuracy assessment of the system shows that the grid deformation measurement accuracy is better than 12 μm, and the system satisfies the requirement of high-precision real-time measurements of the grid thermal deformation of the ion thruster under the discharge-chamber-running condition and the plasma-beam-extraction condition.

2013 ◽  
Vol 718-720 ◽  
pp. 1155-1159
Author(s):  
Ming Shan Yang ◽  
Xiao Chao Meng ◽  
Jia Jia Yan ◽  
Wei Li ◽  
Zhi Yong Qiu

Using the high precision three-dimension thermal deformation measurement equipment, the data of differential linear expansion coefficient of several materials used in microwave equalizer were got, and the thermal deformation of resonant cavity and the probe of typical structural were measured exactly. Therefore, the internal relationship between the thermal deformation and the shift of equalized property can be concluded. According to the precise data of the thermal deformation measured, the methods, such as materials compensation and structural compensation, were used to guarantee the properties of equalizer at different working temperatures.


2014 ◽  
Vol 635-637 ◽  
pp. 1128-1131
Author(s):  
Xing Hong Kuang ◽  
Zhe Yi Yao ◽  
Shi Ming Wang

With the development of economy, the global satellite navigation system with its high speed, high efficiency, high precision measurement and positioning a series of significant advantages, favored by various industry data collection and monitoring of personnel resources , the advent of satellite navigation systems to solve a large-scale, rapid and high-precision global positioning problem. Its scope of application has penetrated to the various departments of the national economic and social development in various fields and industries. To be able to monitor the progressive realization of automated data collection and transmission, the urgent need to adopt advanced positioning technology to build real-time location monitoring system PC Based Development Background navigation receiver , an overview of the inter Beidou BD-126 systems and microcontrollers can be serially the basic principle of mouth communication describes the communication protocol Compass BD-126 positioning module and the next crew between the microcontroller to control development in the use of PC positioning system for a detailed description , including the BDS Beidou satellite navigation module and microcontroller serial data communications, microprocessor controlled real-time data display , and so on


2017 ◽  
Vol 96 (6) ◽  
Author(s):  
C. Fontbonne ◽  
P. Ujić ◽  
F. de Oliveira Santos ◽  
X. Fléchard ◽  
F. Rotaru ◽  
...  

1991 ◽  
Vol 1 (12) ◽  
pp. 1669-1673 ◽  
Author(s):  
Hans Gerd Evertz ◽  
Martin Hasenbusch ◽  
Mihail Marcu ◽  
Klaus Pinn ◽  
Sorin Solomon

IEEE Access ◽  
2019 ◽  
Vol 7 ◽  
pp. 61570-61580 ◽  
Author(s):  
Weichen Li ◽  
Junying Xia ◽  
Ge Zhang ◽  
Hang Ma ◽  
Benyuan Liu ◽  
...  

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Sung Yong Park ◽  
Gina Faraci ◽  
Pamela M. Ward ◽  
Jane F. Emerson ◽  
Ha Youn Lee

AbstractCOVID-19 global cases have climbed to more than 33 million, with over a million total deaths, as of September, 2020. Real-time massive SARS-CoV-2 whole genome sequencing is key to tracking chains of transmission and estimating the origin of disease outbreaks. Yet no methods have simultaneously achieved high precision, simple workflow, and low cost. We developed a high-precision, cost-efficient SARS-CoV-2 whole genome sequencing platform for COVID-19 genomic surveillance, CorvGenSurv (Coronavirus Genomic Surveillance). CorvGenSurv directly amplified viral RNA from COVID-19 patients’ Nasopharyngeal/Oropharyngeal (NP/OP) swab specimens and sequenced the SARS-CoV-2 whole genome in three segments by long-read, high-throughput sequencing. Sequencing of the whole genome in three segments significantly reduced sequencing data waste, thereby preventing dropouts in genome coverage. We validated the precision of our pipeline by both control genomic RNA sequencing and Sanger sequencing. We produced near full-length whole genome sequences from individuals who were COVID-19 test positive during April to June 2020 in Los Angeles County, California, USA. These sequences were highly diverse in the G clade with nine novel amino acid mutations including NSP12-M755I and ORF8-V117F. With its readily adaptable design, CorvGenSurv grants wide access to genomic surveillance, permitting immediate public health response to sudden threats.


Radiocarbon ◽  
2020 ◽  
pp. 1-13
Author(s):  
Alexandra Fogtmann-Schulz ◽  
Sabrina G K Kudsk ◽  
Florian Adolphi ◽  
Christoffer Karoff ◽  
Mads F Knudsen ◽  
...  

ABSTRACT We here present a comparison of methods for the pretreatment of a batch of tree rings for high-precision measurement of radiocarbon at the Aarhus AMS Centre (AARAMS), Aarhus University, Denmark. The aim was to develop an efficient and high-throughput method able to pretreat ca. 50 samples at a time. We tested two methods for extracting α-cellulose from wood to find the most optimal for our use. One method used acetic acid, the other used HCl acid for the delignification. The testing was conducted on background 14C samples, in order to assess the effect of the different pretreatment methods on low-activity samples. Furthermore, the extracted wood and cellulose fractions were analyzed using Fourier transform infrared (FTIR) spectroscopy, which showed a successful extraction of α-cellulose from the samples. Cellulose samples were pretreated at AARAMS, and the graphitization and radiocarbon analysis of these samples were done at both AARAMS and the radiocarbon dating laboratory at Lund University to compare the graphitization and AMS machine performance. No significant offset was found between the two sets of measurements. Based on these tests, the pretreatment of tree rings for high-precision radiocarbon analysis at AARAMS will henceforth use HCI for the delignification.


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