• Title/Summary/Keyword: The development of technology

Search Result 41,971, Processing Time 0.08 seconds

Damage Effect on Glass Fibre Reinforced Plastics under Airflow by a Continuous Wave Laser (연속발진 레이저에 의한 공기 유동에 노출된 유리섬유 강화 플라스틱 손상효과)

  • Lee, Kwang Hyun;Shin, Wan-Soon;Kang, Eung-Cheol
    • Journal of the Korea Institute of Military Science and Technology
    • /
    • v.18 no.3
    • /
    • pp.293-299
    • /
    • 2015
  • We analyzed the damage effect on Glass Fibre Reinforced Plastics(GFRP) under air flow by irradiation of continuous wave near-IR laser. Damage process and temporal temperature distribution were demonstrated and material characteristics were observed with laser intensity, surface flow speed and angle. Surface temperature on GFRP rapidly increased with laser intensity, and the damaged pattern was different with flow characteristics. In case of no flow, penetration on GFRP by burning and flame generation after laser irradiation was appeared at once. GFRP was penetrated by the heat generated from resin ignition. In case of laser irradiation under flow, a flame generated after burning extinguished at once by flow and penetration pattern on GFRP were differently shown with flow angle. From the results, we presented the damage process and its mechanism.

A Trend Study on Collection Development Policy for Science and Technology Information Resources (과학기술정보 장서개발정책에 관한 동향연구)

  • Lee, Seon-Hee;Choi, Hee-Yoon
    • The Journal of the Korea Contents Association
    • /
    • v.9 no.5
    • /
    • pp.337-345
    • /
    • 2009
  • World leading national science technology information institutes provide scientists with R&D information for increasing national competitiveness. Collection development policy is the guidelines for the science technology information institutes that identify information resources and connect them together to build an information network for supporting R&D. In order to draw main elements of the collection development policy for national level science and technology information institutes, this paper analyzed the policies of National Library of Medicine (NLM), British Library (BL), Canada Institute for Scientific and Technological Information (CISTI), and Korea Institute of Science and Technology Information(KISTI). The results of this study can be used as the guidelines for the science and technology information institutes for establishing collection development policy.

Gonadal Development and Reproduction in the Trumpet Shell, Charonia sauliae

  • Kang, Kyoung-Ho;Kim, Jae-Min;Seon, Seung-Cheon;Zhuo, Liang Liang;Lim, Sang-Min;Kim, Hyeon-Jeong
    • The Korean Journal of Malacology
    • /
    • v.25 no.1
    • /
    • pp.29-33
    • /
    • 2009
  • This study devised and tested a histological staging system for gonadal development in the trumpet shell, Charonia sauliae, which was collected along the south coast of Jeju Island, South Korea. This paper details for the first time the gonadal development characteristics of C. sauliae. Ovary and testis development in C. sauliae can be roughly divided into five stages: growing, mature, spent, degenerative, and resting. The trumpet shelll has multiple fecundation and fertilization during the spawning season for out-of-step gonadal development in high-temperature and low-salinity environments. Female trumpet shell tended to have larger shells and were more abundant than males (64.26% of all animals collected were female).

  • PDF

Plasma electrolytic processing for polishing of stainless steel surfaces

  • Van, Thanh Dang;Kim, Sung-W.;Kim, Jong-R.;Kim, Sang-G.
    • Proceedings of the Korean Institute of Surface Engineering Conference
    • /
    • 2008.11a
    • /
    • pp.137-137
    • /
    • 2008
  • This paper presents the ability of plasma electrolytic polishing technology to polish surface of stainless steel materials. The results show that the surface of its can be polished clearly using potentiostatic regimes in various concentration of $(NH_4)_2SO_4$ solution that had been warmed to a certain initial temperature. The equipment and deposition produces for polishing process are described and the effect of processing parameters on the characterizations polishedsamples has been has been investigated.

  • PDF