탄소강재의 회전굽힘응력 하에서의 피로균열의 성장식과 수명예측

강용구,최환,이태원,이종찬 國立金烏工科大學校附設生産技術硏究所 1997 産業技術開發硏究 Vol.13 No.-

In this work, fatigue crack growth equations and Life Predition are studied. New exponential crack growth equation are presented to describe the crack growth behaviors from an artificial pit of three type carbon steels (G. J1 and J2) under rotary bending (R= -1). Crack growth curves obtained from new exponential crack growth equations are in good agreement with experimental data of carbon steels. Fatigue life predition are also carried out by numerical integral method. Predition lives using new exponential crack growth equations and 4th order polynominal crack growth equations are also compared with experimental results. Predition lives obtained from new exponential crack growth equation are in good agreement with the experimental ones. The difference between predition lives and experimental ones are not exceed ±10%. The other hand, in the case of using 4th order polynominal crack growth equations, the difference between predition lives and exprimental ones are exceed ±20%.

선인장 양심실 보조장치의 설계 및 임상적용을 위한 평가

민병구,박찬영,최재순,이혁수,황창모,김삼성,윤걸중,김종원,선경,이경갑,정종태,김원곤 제주대학교 인공심장이식연구소 2001 인공심장 연구 Vol.2 No.1

현재 개발되고 있는 맥동형 이식형 인공심장은 완전이식형 인공심장과 좌심실보조장치 뿐이다. 좌심실보조장치를 장착한 환자의 10~15%가 우심실의 보조를 필요로하고 완전이식형 인공심장의 장착을 위해서는 자연심장을 제거해야하는 상황에서 이식형 양심실보조장치에 대한 필요성이 대두되고 있다. 본 연구진은 완전이식형 인공심장으로 개발된 한국형 인공심장을 개선하여 양심 실 보조장치를 개발하였다. 양심실보조장치는 이동형 작동기식 미케니즘을 이용하고 있으며 에너지 변환장치와 감속기로 구성된 작동기와 혈액주머니, 그리고 내장형 제어기로 구성되어 있다. 선인장 펌프로 명명된 KAH350은 캐뉼라의 연결을 위한 커넥터를 포함하여 길이 177mm, 폭 164mm, 높이 67 이고 무게 780g이며 최대 심박출량은 5L/min 이다. 양심실보조장치로 개발된 선인장펌프는 좌심실보조장치로도 응용이 가능하다. 이식적합성과 생체적합성을 평가하기 위하여 좌심실보조장치로 5회, 양싱실보조장치로 6회의 동물실험을 수행하였다. 각각 최장 28일간 생존하였으며 11회의 동물실험중 장치의 결함에 의한 것이 3회 있었는데 이들은 모두 전자장치의 결함과 방수처리문제였다. 현재 이식적합성과 일박출량을 향상시킨 KAH400모델이 개발중이다. The types of pulsatile implantable artificial hearts that are on the way of development and have been developed are totally implantable artificial heart and implantable left ventricular assist device (LVAD). Approximately 10% to 15% of all patients Implanted with wearable VADs have required right heart support with another device. And it is reluctant to patient who should remove his or her own heart to be implanted with total artificial heart. These situations drive the development of implantable bi-ventricular assist device (BVAD). The Korean BVAD was develophed by modifying the moving actuator type Korean artificial heart. This electro-mechanical BVAD comprises actuator including energy converter and reduction gear train, blood sacs, and internal motor and energy controllers. The KAH350 which is named as 'Cactus Pump' is 177mm in length, 164mm in width, and 67mm in thickness including connectors and nuts. The weight and maximum cardiac output of Cactus Pump is 780g and 5L/min, respectively. The Cactus Pump that was developed as BVAD could be used as LVAD by attaching compliance caps on the 2 ports of one ventricle. The animal experiments were undergone 5 times for LVAD, and 6 times for BVAD. The best records were 28 days survival in both applications. There were 3 times of device failure and they were all associated with electrical connection and hermetic sealing. The KAH400 that has improved anatomical fitting characterisitcs and stroke volume is on development.

세라믹 종류에 따른 코어링 특성에 관한 연구

강용구,이태원,이종찬,최환 金烏工科大學校 産業技術開發硏究院 1999 産業技術開發硏究 Vol.15 No.-

A diamond core drill has been well carried out in the ceramics drilling. In this investigation, a vertical type machining center (MC) was used in the coring of Al₂O₃and Si₃N₄ceramics with a metal bonded diamond core drill. To clarify the mechanism of coring, the influences of coring conditions on the coring force, grinding ratio, succesive zone of coring were studied. At the wheel feed speed of 5.2 mm/min, and the wheel revolution of 3000rpm in Al₂O₃ceramics, the wheel speed of 2.7 mm/min, and the wheel revolution of 1500rpm in Si₃N₄ceramics, the best grinding ratio was obtained. But, from a viewpoint of coring speed, the wheel feed speed at 37 mm/min (Al₂O₃) and 10 mm/min (Si₃N₄) were best, when the coring depth was to 1 mm.

우리나라 중부지방의 시설원에 토양 및 지하수 환경

김진호,이종식,김원일,정구복,윤순강,정연태,권순국 한국환경농학회 2002 한국환경농학회지 Vol.21 No.2

연구대상 시설재배지 토양의 물리성은 대부분이 모래의 비율이 높은 sandy loam이나 loam으로 투수성이 양호할 것으로 판단되나, P2나 S1에서는 미사의 비율이 높은 미사 loam으로 투수성 및 통기성이 상대적으로 낮은 것으로 판단된다. 토양의 화학성은 EC의 경우 표토의 대부분이 기준치에 도달하거나, 초과하는 경향이었고, 심토의 경우는 기준치 이하로 조사되었다. 또한 유기물 함량은 적정수준 2~3%보다 조사 대상 지점의 대부분에서 상회하였고, 심토의 일부분도 이 수준을 넘는 곳도 있었다. 조사 대상 지역의 수질 특성 중 시설재배지 지하수의 가장 중요한 염류 지표인 EC는 연평균 0.48 dS/m로 농업용수로서 작물에 미치는 영향은 없는 것으로 판단되나, 수질오염지표인 질산성 질소의 경우 19.1 mg/L 로 농업용수 수질 기준인 20 mg/L에 근접한 수준을 나타내었다. 특히 조사 대상 지점의 36.4%가 수질 기준을 초과하는 것으로 나타났다. 지하수중의 이온의 양과 영양염류의 양을 간접적으로 나타내는 전기전도도인 EC는 양이온인 경우 Mg^(2+), Ca^(2+), Na^+, K^+와 정의상관이 있었으며, 특히 2가 양이온인 Mg^(2+)와 Ca^(2+)간에는 고도의 정의상관을 보이고 있었다. 또한 EC와 음이온간에는 NO_3^-, Cl^-, SO_4^(2-), PO_4^(2-)와 상관을 보이고 있었다. 지하수의 오염지표인 NO_3-N의 경우에는 COD를 제외한 모든 이온들과 상관을 보이고 있었다. 특히 SO_4^(2-), Cl^-, Na^+, Ca^(2+), Mg^(2+)와는 고도의 정의 상관을 보여주고 있다. 이는 NO_3-N는 EC와 함께 지하수오염의 중요한 지표중의 하나임을 보여주고 있다. The objective of this study was to know the qualities of soil and shallow groundwater in plastic film house fields around Central Part of Korea. The study was conducted at 11 sites in Suweon, Hwasung, Pyungtaek, Yongin, and Chuncheon through May to August in 1999. Soil textures of plastic films house were mainly sandy loam or loam. Electric conductivity and organic matter content of surface soils mostly exceeded the critical levels for crop production. Average concentration of N0_3-N in the shallow groundwater was 19.1 mg/L, and it reached almost the limiting level of agricultural groundwater quality (20 mg/L). Moreover about 36% of survey sites exceeded the limiting level of agricultural groundwater quality. Sulfate concentrations also at some sites exceeded agricultural groundwater quality limit level (50 mg/L). Nitrate-N, one of the most important factors in the groundwater quality, had positive correlations with other ions in groundwater.

Effect of a Bombyx mori Protein Disulfide Isomerase on Production of Recombinant Antibacterial Peptides

Goo, Tae-Won,Kim, Seong-Wan,Choi, Kwang-Ho,Kim, Seong-Ryul,Kang, Seok-Woo,Park, Seung-Won,Yun, Eun-Young Korean Society of Sericultural Science 2013 International Journal of Industrial Entomology Vol.26 No.2

The insect baculovirus expression vector system (BEVS) is useful for producing biologically active recombinant proteins. However, the overexpression of heterologous proteins using this system often results in misfolded proteins and the formation of protein aggregates. To overcome this limitation, we developed a versatile baculovirus expression and secretion system using Bombyx mori protein disulfide isomerase (bPDI) as a fusion partner. bPDI gene fusion was found to improve the secretions and antibacterial activities of recombinant nuecin and enbocin proteins. Thus, we conclude that bPDI gene fusion is a useful addition to BEVS for the large-scale production of bioactive recombinant proteins.

A Strong Transcription Activity of the Bombyx mori Elongation Factor 1α Promoter

( Tae Won Goo ),( Sung Wan Kim ),( Seong Ryul Kim ),( Seung Won Park ),( Seok Woo Kang ),( Kwang Ho Choi ),( Eun Young Yun ) 한국잠사학회 2012 International Journal of Industrial Entomology Vol.24 No.2

We previously isolated 9 clones that show stronger signal compared to B. mori cytoplasmic action gene(BmA3) by using a dot blot hybridization. In this study, we focused on one clone among these clones which has high amino acid homology with elongation factor α gene of B. mori. This clone, named bEF1α(B. mori elongation factor α) was ubiquitously expressed in all tissues and developmental stage of B. mori. As result of promoter assay using dual luciferase assay system, we found the highest transcription activity region (-702/+38) in the 5`-flangking region of bEF1α gene, which has about 20 fold more intensive promoter activity than BmA3 promoter. Moreover, the bEF1α promoter was normally regulated in Bm5, Sf9, and S2 cells. Therefore, we suggest that bEF1α promoter may be used more powerful and effectively for transgene expression in various insects containing B. mori as a universal promoter.

Expression of the cyan fluorescent protein in fibroin H-chain of transgenic silkworm

( Tae-won Goo ),( Kwang-ho Choi ),( Seong-ryul Kim ),( Seung Won Park ),( Seong-wan Kim ) 한국잠사학회 2017 International Journal of Industrial Entomology Vol.34 No.1

We constructed the fibroin H-chain expression system to produce enhanced cyan fluorescent proteins (ECFP) in transgenic silkworm cocoon. Fluorescent cocoon could be made by fusing ECFP cDNA to the heavy chain gene and injecting it into a silkworm. The ECFP fusion protein, each with N- and C-terminal sequences of the fibroin H-chain, was designed to be secreted into the lumen of the posterior silk glands. The expression of the ECFP/H-chain fusion gene was regulated by the fibroin H-chain promoter. The use of the 3xP3-driven EGFP cDNA as a marker allowed us to rapidly distinguish transgenic silkworms. The EGFP fluorescence became visible in the ocelli and in the central and peripheral nervous system on the seventh day of embryonic development. A mixture of the donor and helper vector was micro-injected into 1,020 Kumokjam, bivoltin silkworm eggs. We obtained 6 broods. The cocoon was displayed strong blue fluorescence, proving that the fusion protein was present in the cocoon. Accordingly, we suggest that the ECFP fluorescence silk will enable the production of novel biomaterial based on the transgenic silk. ⓒ 2017 The Korean Society of Sericultural Sciences Int. J. Indust. Entomol. 34(1), 11-15 (2017)

A Strong Transcription Activity of the Bombyx mori Elongation Factor 1α Promoter

Goo, Tae-Won,Kim, Sung-Wan,Kim, Seong-Ryul,Park, Seung-Won,Kang, Seok-Woo,Choi, Kwang-Ho,Yun, Eun-Young Korean Society of Sericultural Science 2012 International Journal of Industrial Entomology Vol.24 No.2

We previously isolated 9 clones that show stronger signal compared to B. mori cytoplasmic actin gene (BmA3) by using a dot blot hybridization. In this study, we focused on one clone among these clones which has high amino acid homology with elongation factor ${\alpha}$ gene of B. mori. This clone, named $bEF1{\alpha}$ (B. mori elongation factor ${\alpha}$) was ubiquitously expressed in all tissues and developmental stage of B. mori. As result of promoter assay using dual luciferase assay system, we found the highest transcription activity region (-702/+38) in the 5'-flanking region of $bEF1{\alpha}$ gene, which has about 20 fold more intensive promoter activity than BmA3 promoter. Moreover, the $bEF1{\alpha}$ promoter was normally regulated in Bm5, Sf9, and S2 cells. Therefore, we suggest that $bEF1{\alpha}$ promoter may be used more powerful and effectively for transgene expression in various insects containing B. mori as a universal promoter.

Secretion of the Antibacterial Recombinant Protein Enbocin

Goo, Tae Won,Yun, Eun Young,Kim, Sung Wan,Choi, Kwang Ho,Kang, Seok Woo,Kwon, Kisang,Choi, Joung-Soon,Kwon, O-Yu Walter de Gruyter GmbH 2008 Zeitschrift fur Naturforschung. Section C Vol.63 No.3

<P>The insect baculovirus expression vector system (BEVS) is useful for the production of biologically active recombinant proteins. However, the overexpression of foreign proteins in this system often results in misfolded proteins and the formation of protein aggregates. To overcome this limitation, we have developed a versatile baculovirus expression and secretion system using the Bombyx mori protein disulfide isomerase (bPDI) as a fusion partner. bPDI gene fusion improved the secretion and antibacterial activity of recombinant enbocin proteins. Thus, bPDI gene fusion is a useful addition to the BEVS for the large-scale production of bioactive recombinant proteins</P>

Utilization of the Bombyx mori Hypothetical Protein 32 Promoter for Efficient Transgene Expression

Goo, Tae-Won,Kim, Sung-Wan,Kim, Seong-Ryul,Park, Seung-Won,Kang, Seok-Woo,Lee, Kwang-Gill,Kwon, O-Yu,Yun, Eun-Young Korean Society of Sericultural Science 2010 International Journal of Industrial Entomology Vol.20 No.2

For stable germline transformation, the promoter of Bombyx mori cytoplasmic actin gene (BmA3) has been used for ubiquitous expression of transgenes. So far, no strong promoter is available for ubiquitous expression in B. mori, excluding BmA3 promoter. To identify more powerful promoter than previously reported BmA3 promoter, we isolated 9 clones that show stronger signal compared to BmA3 by a dot blot hybridization. Among these 9 clones, we focused on one clone which has high amino acid homology (85%) with hypothetical protein 32 gene of Lonomia obliqua. This clone, named bHp32 (B. mori hypothetical protein 32) was ubiquitously expressed in all tissues and developmental stage of fifth instar B. mori larvae. As result of promoter assay using dual luciferase assay system, we found the highest transcription activity region (-1,200/+220) in the 5'-flanking region of bHp32 gene, which has 42-fold more intensive promoter activity than BmA3 promoter. Moreover, the bHp32 promoter was normally regulated in Bm5, Sf9, and S2 cells. Therefore, we suggest that bHp32 promoter may be used more powerful and effectively for transgene expression in various insects containing B. mori as a universal promoter.