Poplar 組織培養에 의한 anthocyanin 生成

李承雨,崔根元,鄭印植 경희대학교 유전공학연구소 1993 遺傳工學論文集 Vol.5 No.-

Poplar(Populus nigra)를 대상으로 組織培養時 callus 生長과 anthocyanin形成에 影響을 미치는 環境條件으로써 最適培地, 糖의 效果, 植物生長調節劑, 糖의 種類 및 日長의 影響을 검토하고자 遂行한 결과는 다음과 같이 요약된다. 1. SH 培地가 callus 및 anthocyanin형성에 효과적이었고 sucrose濃度는 5.5%가 우수하였다. 2. Auxin류의 효과에 있어서는 2,4-D 2.0 ㎎/ℓ에서 callus 및 anthocyanin형성에 가장 효과적 이었다. 3. Cytokinin류에서 BA가 kinetin에 비하여 callus生育을 顯著하게 抑制하였고 kinetin 0.2㎎/ℓ에서 anthocyanin형성이 가장 우수하였다. 4. 糖의 종류로는 fructose가 sucrose나 glucose에 비하여 callus增殖에 월등히 높은 효과를 보였고 anthocyanin形成量에는 큰 차이를 보이지 않았다. 5. 日長의 效果에서 anthocyanin形成은 日長이 길어질수록 促進되었으며 callus형성은 日長에 따른 차이를 보이지 않았다. The experiments were conducted to optimize culture conditions for callus growth and anthocyanin formation by in vitro culture of Populus nigra through tests of basal media, inorganic salts, plant growth regulators, sucrose concentrations, sugar and photoperiods. SH media supplemented with 55 g/l sucrose gave the best results in callus and anthocyanin formation. For the effects of plant growth regulators, anthocyanin formation was promoted by treatment with 2.0 ㎎/l 2,4-D. On the other hand, 0.2 ㎎/l kinetin showed the highest activity for anthocyanin synthesis while BA severely suppressed callus growth. Fructose compared with glucose remarkably promoted callus growth but anthocyanin formation showed no difference with sugar type. Anthocyanin pigment accumulation hastened by increasing photoperiod in culture room while callus growth was not affected with photoperiod.

PIV계측에 의한 충돌제트에서 사각 난류촉진체 주변의 유동특성 연구

李相範,孫承佑,宋旼根,朱恩選 경상대학교 생산기술연구소 2001 工學硏究院論文集 Vol.1 No.-

The objective of this study is to investigate characteristics of flow by the square turbulence promoter and the selection of a proper impinging distance. The promoter was set up vertically to the way of a nozzle exit flow, each pitch fixed to be 30㎜ and the measurement region divided by 4 section(A, B, C, D). The characteristics of flow field were investigated in each case of the distance rate from the nozzle exit to impinging plate(H/B=4, 6, 8, 10) changing nozzle exit diameter(Ψ10, 17, 23) and Re=4,000. As the experimental result by using PIV measurement at Ψ17 and H/B=6 in the free jet, the turbulence intensity showed a big strength at A section, a decreasing of 20.1% at B section, an increasing of 10% at C section and an increasing of 10.9% at D section. On the other side, when the square turbulent promoter set up, The flow showed a tendency with the free jet at A section, a decreasing of 16.2% at B section, a decreasing of 1.5% at C section and an increasing of 8.3% at D section, It has been shown that for enhancing the turbulence intensity are the case of Ψ17 and H/B=8 in the B section is the propel condition.

티타늄 레이저 용접부의 기계적 성질 평가

이중재,김길수,안승근,배태성,박찬운 大韓齒科器材學會 2003 대한치과재료학회지 Vol.30 No.2

This study was performed to examine the effects of laser output energy on the mechanical properties of laser-welded titanium joints. Titanium rods of 3 ㎜ in diameter were perpendicularly cut to 30 ㎜ in length for the laser welding. Two rods were fixed to each other with a jig and welded vertically using a Nd:YAG laser at output current of 210-270 A. The penetration depth of the laser beam against the titanium was measured with the changes of output current, pulse duration, and spot diameter. Mechanical tests included tensile testing and Vickers microhardness of the joints. Tensile testing was performed at the crosshead 00speed of 1.0 ㎜/min and a gauge length of 30 ㎜ with a universal testing machine. Vickers microhardness was mesured under 9.8 N load for 15 seconds. The results obtained were summarized as follows; With increasing the output current, the penetration depth of the laser to titanium was increased. Tensile strength values of laser-welded groups were the relatively higher than that of non-welded parent material group. There were significant differences in tensile strength between the specimens of laser-welded at output currents 250 A, 270 A and non-welded parent material group(p<0.05). Microhardness values were increased in the heat-affected zone. Brittle fracture regions were observed in the specimens of laser-welded at output currents 270 A.

접촉각 측정을 통한 Alkanethiol로 표면 처리한 은 분말의 표면 특성 연구

이길재,신승일,오성근 한국공업화학회 2004 공업화학 Vol.15 No.1

은 분말을 alkanethiol로 표면 처리한 후, alkanethiol의 탄소 개수 변화에 따른 은 입자의 표면 특성변화를 접촉각 측정을 통해 연구하였다. 이때 은 입자 표면에 alkanethiol의 흡착여부를 DRIFT (diffuse reflectance infrared fourier transform) spectrum를 통해 확인하였다. 접촉각은 Washburn 식을 바탕으로 한 liquid penetration 방법으로 측정하였고, 이 측정법의 보완을 위해 분말에 압력을 가하여 원판형태로 만들어 그 표면에서 접촉각을 측정하는 sessile drop 방법을 함께 사용하였다. 그 결과 순수한 은 입자의 물에 대한 접촉각은 두 가지 방법에 대해 각각 58°, 40° 나왔고, 다양한 탄소개수(C_(4)-C_(12))의 alkanethiol로 표면 처리한 입자는 모두 90° 이상의 결과를 얻었다. 즉 alkanethiol로 처리한 은 입자의 표면이 소수성으로 변했음을 의미한다. 여기서 처리한 alkanethiol의 탄소개수가 증가할수록 접촉각은 계속 증가했으나, 접촉각의 증가 폭은 상대적으로 점차 감소하였다. Contact angles of silver powders were measured for investigation of surface properties of silver particles as changing alkyl chain length of alkanethiol. Silver powders were modified by various alkanethiol (C4∼C12). Adsorption of alkanethiol on silver particles was confirmed by DRIFT (diffuse reflectance infrared fourier transform) spectrum. Contact angles were measured by liquid penetration method based on Washbum equation and sessile drop method on tablet of compressed powder. In result. the value of contact angles on water were 53°, 40°about two method. Contact angles of surface treated particles by alkanethiol of varied alkyl chain length were larger than 90°. Because of bonding between silver and sulfur in alkanethiol, silver surface was surrounded by alkyl groups of alkanethiol. Surface properties of silver particles were increased on hydrophobicity with alkyl chain length of alkanethiol. In comparison with increase of contact angle accordingto increase of alkyl chain length of alkanethiol. the widths of increasing contact angle were relatively decreased.

인천신공항의 성공적 개항을 위한 서비스전략

이승창,차근호 한국항공대학교 경영연구소 1998 경영연구 Vol.5 No.1

Today's successful hubs are trying to continue to keep up with the variety of customers' needs - airlines and passengers. It is very useful to employ marketing concept for airport management. The authors studied several cases in European and American network. Important factors such as checking process, baggages claim procedure, sign postage, and so on have been found and standardized for IIA. More for the successful launching was new public relations strategy proposed with examples.

Digital Subtraction Angiography (DSA)시 Grid 사용유무에 따른 화상변화에 관한 연구

이성길,김승국,김영근 광주보건대학 1990 論文集 Vol.15 No.-

It has been investigated the variation of the image for using and no using the Grid at the D.S.A(Digital Subtraction Angiography) system. The result of experiment indicated that in the case of no using the Grid, (1) the irradiation dose of patient was reduced and the life of X-ray tube prolonged. (2) the variation of the contrast was not influence of using the Grid.

급성 B형 간염의 회복 후 말초혈액 단핵구에서의 HBV DNA검출

명승재,이영상,김형건,이근찬,박능화,정영화,서동진 大韓消化器病學會 1997 大韓消化器病學會誌 Vol.29 No.1

저주파음에 의한 자리돔, Chromis notatus의 청각 능력 : 청각 문턱치

이창헌,서익조,오승훈,김병엽,서두옥,김동근 제주대학교 해양과환경연구소 2001 해양과환경연구소 연구논문집 Vol.25 No.-

In order to obtain the fundamenal data about method of luring fish schools by underwater sound, this experiment was carried out to investigte the auditory threshold of coralfish Chromis notatus which was on the coast of Jeju island by heartbeat conditioning technique using pure tones coupled with a delayed electric shock. The coralfish could hear a sound in the frequency range from 80 ㎐ to 800 ㎐. The mean auditory thresholds of coralfish at the frequencies of 80 ㎐, 100 ㎐, 200 ㎐, 300 ㎐, 500 ㎐ and 800 ㎐ were 100 ㏈, 99 ㏈, 91 ㏈, 88 ㏈, 96 ㏈ and 114 ㏈, respectively. As the frequency became higher than 300 Hz the auditory threshold increased rapidly.

保證信用狀(Standby L/C)의 問題點

李鍾根,李昇勳 경북대학교 경제경영연구소 1992 經商論集 Vol.20 No.1

복숭아의 재배 및 저장기간 중 Procymidone, Chlorpyrifos 및 Cypermethrin의 잔류량 변화

이용재,고광용,원동준,길근환,이규승 한국환경농학회 2003 한국환경농학회지 Vol.22 No.3

복숭아의 생산단계에서 잔류허용 기준과 최종 소비단계에서의 잔류양상 평가자료로 활용하기 위하여 복숭아에서의 procymidone, chlorpyrifos 및 cypermethrin의 포장상태에서와 실온(20°C) 및 저온(4°C) 저장시 잔류양상을 알아보았다. Procymidone의 포장상태에서의 반감기는 표준량 3.1, 배량 3.4일로 나타났고, chlorpyrifos는 포장상태에서 포준량 7.2, 배량 5.8일로 나타났으며, cypermethrin은 표준 10.1, 배량 14.4일로 나타났다. 약제 살포 후 초기 부착량이 MRL 이하로 내려갈 때까지의 시간을 계산해 본 결과 배량으로 살포 할 경우 procymidone과 chlorpyrifos는 안전사용기준 보다 시간이 오래 걸렸지만, 표준량으로 사용할 경우 별다른 문제가 없는 것으로 나타났다. 저장기간 중의 procymidone, chlorpyrifos, cypermethrin의 반감일수는 20°C에서 4.6, 10.2, 12.9일 이며, 4°C에서는 16.1, 14.3, 13.1일로 저온에서의 반감기가 실온에서보다 더 긴 것을 알 수 있었다. 한편 세척방법에 의한 잔류농약의 제거율은 수돗물에서는 최고 procymidone 82.9%, chlorpyrifos 27.0%, cypermethrin 24.0%로 나타났고, 세제를 사용 할 경우 procymidone 88.8%, chlorpyrifos 59.0%, cypermethrin 59.4%의 제거율을 보였다. The residue patterns of procymidone, chlorpyrifos and cypermethrin in peaches were examined. The pesticides were sprayed at 15 days before harvest and then were determined the residue at 0, 1, 2, 3, 5, 7, 10 and 15 days after pesticide application and calculated their DT_(50). Also, the degradation patterns at 4℃ and 20℃ during storage period were compared. Biological half-lives of procymidone, chlorpyrifos and cypermethrin in peaches during the cultivation period were 3.1, 7.2 and 10.4 days, respectively. The biological half-life of procymidone was shorter than the others. During the storage period, half-lives of procymidone, chlorpyrifos and cypermethrin were 16.0, 14.3 and 13.1 days at 4 C and 4.6, 10.2 and 12.9 days at 20℃, resp ectively. The degradation rates of these three pesticides in storage period were slower than them in cultivation period. Removal rates were 22.2--82.9% by tap water, and 12.5∼88.8% by detergent solution.