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Development of C/SiC Composite Parts for Rocket Propulsion (로켓 추진기관용 C/SiC 내열부품 개발)

Kim, Yunchul;Seo, Sangkyu
- Journal of the Korean Society of Propulsion Engineers
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- v.23 no.2
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- pp.68-77
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- 2019
C/SiC composites were developed by a liquid silicon infiltration(LSI) method for use as heat-resistant parts of solid and liquid rocket propulsion engines. The heat resistance characteristics according to the composition ratio (carbon / silicon / silicon carbide) were evaluated by specimen test through arc plasma, supersonic torch test. An ablation equation for oxidation reactions was presented. Through the combustion test it was verified that various parts such as nozzle insert, exit cone and combustion chamber heat resistant parts for rocket propulsion can be manufactured and proved high ablation performance and thermal structure performance.
https://doi.org/10.6108/KSPE.2019.23.2.068 인용 PDF KSCI

Variation of Leaflet Traits and Their Association with Agronomic Traits of Soybean Germplasm (콩 유전자원의 소엽형질 변이와 농업형질과의 관계)

Yeong Ho, Lee;Yung Kuang, Huang
- KOREAN JOURNAL OF CROP SCIENCE
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- v.42 no.5
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- pp.640-646
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- 1997
To determine variations in leaflet length (LL), leaflet width (LW), leaflet size (LS), and leaflet shape index (LSI), and their association with eight agronomic traits, characterization data of 884 soybean accessions which were grown in the autumn of 1992 in Taiwan were analyzed. LL ranged from 4.3 to 14.7 cm, and LW ranged from 2.8 to 9.7 cm. Also, LS (LL $\times$ LW) ranged from 12.1 to 124.6 $\textrm{cm}^2$. The absolute variation of LL, LW, and LS was not large because of limitation in vegetative growth by short day length. None was classified as a large leaflet based on the International Board for Plant Genetic Resources (IBPGR) descriptors. LSI (LL /LW) ranged from 1.21 to 3.06, and three accessions were classified as narrow leaflet. There were differences in ranges and means of LL, LW, LS, and LSI between and within temperate and tropical accessions. LL, LW, LS, and LSI had highly significant positive correlations with seven agronomic traits and highly significant negative correlation with 100-seed weight except LW for all accessions. There was variation in the closeness of association among leaflet traits, and between and within temperate and tropical accessions. Generally, LL, LW, and LS were more closely associated with days to flowering, plant height at $R_1$ and $R_8$, number of pods per plant; LSI was more closely associated with 100-seed weight than other traits.
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