Application of different cell disruption methods for lipid extraction from Botryococcus braunii

Kwang?kuk Cho,Hai?Linh Tran,Choul?Gyun Lee 한국생물공학회 2010 한국생물공학회 학술대회 Vol.2010 No.10

유사체액에서의 전기화학적 처리가 티타늄 표면의 인산갈슘 흡착에 미치는 영향

조국현,김문영,송광엽,배태성,이민호 大韓齒科器材學會 2002 대한치과재료학회지 Vol.29 No.3

This study was performed to examine the effect of electrochemical treatment on the precipitation of apatite-like calcium phosphate in a simulated body fluid. Titanium plates of 20×20×1 ㎣ in dimensions were polished sequentially from #600 to #2,000 emery paper and one surface of each specimen was received an additional polishing sequence through 0.1㎛ alumina paste. To improve the bioactivity of titanium plates, they were electrochemically treated at 100 mA for 20 min in an electrolyte containing the calcium and phosphate ions, and the Hanks' solution with pH 7.4 at 36.5℃ for 30 days, and the surfaces were examined with X-ray diffractometer(XRD), scanning electron microscope(SEM) and X-ray photoemission spectroscopy(XPS). Precipitation of calcium phosphate and CaO were observed on the electrochemically treated titanium surface in a simulated body fluid after treatment at 600℃. Precipitation of calcium phosphate was densified and coarsened with increasing the temperature of the electrolyte solution in the range of 20-80℃. The calcium phosphate contained phosphate in the form of Po₄^3-, HPO₄^2-, and H₂PO₄^-.

강우시 채수빈도가 논 오염부하량 산정에 미치는 영향

한국헌,김진호,이종식,이정택,조재영,윤광식 한국환경농학회 2005 한국환경농학회지 Vol.24 No.1

한정된 수질자료를 이용 오염부하 산정시 집중적으로 많은 샘플을 채취한 경우에 비해 어느 정도 차이를 갖는지를 규명하는 것은 모니터링에 따른 오염부하량 산정결과의 신뢰 범위 파악뿐만 아니라 경제적인 수질 샘플 채수빈도 수립에 곡 필요한 것으로 사료된다. 그 결과를 요약하면 다음과 같다. 논에서의 강우-유출시 채수 빈도가 오염부하 산정에 미치는 영향을 파악하기 위해 9개의 강우사상에 대해 2시간 간격으로 연속 수질샘플을 실시하여 분석한 결과 전체적으로 강우-유출과정 중 T-N, T-P, SS 농도는 시간별로 증·감변동을 하였으나 유량과의 상관성은 나타나지 않았다. 수질샘플 횟수에 의한 영향은 강우-유출과정 중 5회 정도 샘플을 실시하면 많은 수의 샘플을 채수한 경우에 비해 T-N ±15.2%, T-P는 -20.0~26.2%, SS는 -28.6~35.7% 범위안에서 오염부하를 추정할 수 있는 것으로 나타났으며, 차이범위가 ±10% 내에 들어가기 위한 샘플수는 일주기 조사시 T-N, T-P의 경우는 6회, SS의 경우는 단기유출시는 4회 정도 실시하면 되고, 장기 유출시에는 11회 정도 실시하면 되는 것으로 조사되었다. 유량-유하부하량 관계식으로 ±10%내의 차이를 보일 샘플횟수는 T-N의 경우는 6회 이상, T-P와 SS는 9회 이상 정도 실시하면 되는 것으로 조사되었다. In order to examine effects of sampling frequency during rainfall-runoff process from paddy field on the estimation of pollution load, EMCs of several water sampling frequencies were examined. Water quality samples were conducted by every two hours interval for each event. It was found that difference of load estimation between five times sampling and two hours consecutive sampling during rainfall-runoff showed 15.2~-15.2% for T-N, 20.0~-26.2% for T-P, 28.6~-35.7% for the SS, respectively. In the same way, the effects of number of sampling data on estimation of pollution load using runoff-mass load(L-Q) method were investigated. L-Q equation made of five times sampling data provided 10% differences in estimation of mass loads of T-N, T-P, and SS when compared to those by L-Q equation using entire two hours consecutive sampling data during runoff process.

유동층을 이용한 탈황제의 마모특성에 관한 연구

오광중,김형국,최은화,조기철 부산대학교 환경문제연구소 1999 環境硏究報 Vol.17 No.1

For the efficient energy use and the protection of environmental pollution, attrition characteristics, depending on the component and the condition of sorbent for the purification of fuel gas, were analyzed by a fluidized-bed tester. Results of these studies can be summarized follows. 1) When Mn-based sorbent(M, MT, MFT) prepared with varying addictives and induration conditions was compared in terms of particle size distribution and AI(Attrition Index), MT and MFT possessing TiO2 and Fe203 had much higher attrition resistance than M. Attrition resistance of M, MT and MFT increased as bentonite contents and induration temperature increased, when bentonite contents induration temperature were changed from 2 to 5% and from 1000 to 1100℃, respectively. Therefore when powdery catalysts are prepared, the attrition rate can be considerably affected by the controls of addictive, binder and induration temperature. 2) Attrition tests using MT1100-5 were performed under the conditions that particle size distribution was uniform and had much more over +270mesh and under -325mesh. AI due to attrition was 8.83, 21.54 and 1.67%, respectively. Thus, initial particle size distribution showed a great influence on both produced fines distribution and attrition loss. Therefore, the size distribution of particles injected initially and the particle size that carried over showed be considered to reduce the loss of particulate materials and the replacement cost due to attrition. 3) An experiment using MT1100-5 sorbent was also carried out to predict AI as a function of time and particle size distribution during 23hr. AI of prepared sorbent was 4.54, 7.73, 9.08, 11.35 and 12.48 after 1.5, 3, 5, 9 and 23hr. respectively. Thus, it was shown that the amount of produced fines during the same time was shorten with the increase of time. The operating condition of dust capturing equipment and the rate of powder exchange needs to be considered because most of the fines due to fluidization of particulate material was generated at initial operation.

Improvement of Biodiesel Production using Various Light Source on Microalgae

Kwang-Kuk CHO,Dong-Keon KIM,Choul-Gyun LEE 한국생물공학회 2011 한국생물공학회 학술대회 Vol.2011 No.4

경사지(傾斜地)에서의 토양유실(土壤流失) -지형인자(地形因子)를 중심으로-

조국광 ( Kuk Kwang Cho ),박성우 ( Sung Woo Park ) 한국농공학회 1981 韓國農工學會誌 : 전원과 자원 Vol.23 No.2

土壤流失은 降雨의 性質, 土壤의 特性, 傾斜度 및 傾斜長, 栽培方法에 따라 달라진다. 따라서 土壤流失을 正確하게 豫測하기 爲해서는 위의 6個 因子에 對한 究明이 必要하다. 지금까지 우리 나라에서는 Wischmeier의 土壤流失量 公式(USLE)을 效率的으로 適用하기 爲하여 6個 因子中 降雨因子, 土壤浸蝕性 因子, 作物因子 및 土壤保全因子에 對해서만 硏究가 있는 實情이다. 따라서 本 硏究에서는 傾斜地에서의 傾斜長가 傾斜度가 土壤流失에 미치는 영향을 究明하여 LS 方程式을 誘導하고자 하였다. 京畿道 驪州郡 梁巨里에 있는 農業振興公社 農地保全 試驗圃에서 10個의 裸地 試驗區에 對한 土壤流失量을 測定하여 分析하였다. 10個의 試驗區中 9個는 傾斜度 10%, 20% 및 30% 各各에 對해 10m, 20m 및 30m의 傾斜長으로 되어 있으며, 나머지 1個의 試驗區는 다른 試驗區와의 比較를 爲한 標準區로서 15%의 傾斜度, 20m의 傾斜長으로 되어 있다. 土壤은 禮山統에 속하며 60%의 砂質, 24%의 微砂質 및 16%의 粘土質로 구성되어 있다. 20回의 土壤流失量 測定記錄中 12.7mm以上의 降雨에 依한 9回分의 流失量 測定資料를 回歸分析한 結果 다음과 같은 LS方程式이 유도되었다. 卽, 그러나 傾斜度와 傾斜長因子(LS)는 다른 여러 因子들과의 相互作用(interaction)을 內包하고 있기 때문에 앞으로의 LS因子에 對한 硏究는 여러種類의 土壤에서 傾斜의 條件을 多樣하게 變化시켜 長期間 實驗을 한다면 韓國의 土壤特性에 一般的으로 適用할 수 있는 LS方程式을 誘導할 수 있으리라 思料된다.

가중회귀분석(加重回歸分析)에 의한 지역화왜곡계수(地域化歪曲係數)의 추정(推定)

조국광 ( Cho Kuk Kwang ),권순국 ( Kwun Soon Kuk ) 한국농공학회 1990 韓國農工學會誌 : 전원과 자원 Vol.32 No.1

The application of the Log-Pearson Type m distribution recommended by Water Resources Council, U. S. A. for flood frequency analysis requires the estimation of the regionalized skew coefficient. In this study, regionalized skew coefficients are estimated using a weighted regression model which relates at-site skews based on logarithms of observed annual flood peak series to both basin characteristics and precipitation data in the Han river and the Nakdong river basin. The model is developed with weighted least squares method in which the weights are determined by separating residual variance into that due to model error and due to sampling error. As the result of analysis, regionalized skews are estimated as - 0.732 and - 0.575 in the Han river and the Nakdong river basin, respectively.

공중 근무자의 영양권장량에 대한 고찰

조태웅,김광수,최용국 공군본부 의무감실 1971 항공의학 Vol.19 No.1-2

Association Study Analysis of Cluster-of-Differentiation Antigen 9 (CD9) Gene Polymorphism (g.358A>T) for Duroc Boar Post-thawed Semen Motility and Kinematic Characteristics

Cho, Eun-Seok,Sa, Soo-Jin,Kim, Ki-Hyun,Lee, Mi-Jin,Ko, Jun-Ho,Kim, Young-Ju,Seol, Kuk-Hwan,Hong, Joon-ki,Kim, Kwang-Sik,Kim, Yong-Min,Woo, Jae-Seok The Korean Society of Embryo Transfer 2015 한국동물생명공학회지 Vol.30 No.2

Cryopreservation of boar semen is continually researched in reproductive technologies and genetic resource banking in breed conservation. For evaluating the boar semen quality, sperm motility (MOT) is an important parameter because the movement of spermatozoa indicates active metabolism, membrane integrity and fertilizing capacity. Various researches have been trying to improve the quality of semen post-thawed in boar. Recently, polymorphism (g.358A>T) of cluster-of-differentiation antigen 9 (CD9) gene reported to be significant association with MOT. Also, CD9 gene was expressed in the male germ line stem cells is crucial for sperm-egg fusion, and was therefore selected as candidate gene for boar semen. This study was conducted to evaluate the pig SNP (g.358A>T) of CD9 gene as a positional controlling for semen parameters of post-thawed boar semen. To results, the g.358A>T SNP of the CD9 gene was significantly associated with the traits such as MOT, curve linear velocity, straight line velocity, average path velocity and amplitude of lateral head displacement. Particularly, the g.358A>T SNP significantly has the highest association with MOT and animals with AA genotype (p<0.001). Therefore, we suggest that the g.358A>T in the intron 6 region of the porcine CD9 may be used as a molecular marker for Duroc boar Post-thawed semen quality, although its functional effect was not defined yet.

Effect of Dome Curvature on Failure Mode of Type4 Composite Pressure Vessel

Cho, Sung-Min,Kim, Kwang-Seok,Lee, Sun-Kyu,Jung, Geun-Sung,Lee, Seung-Kuk,Lyu, Sung-Ki Korean Society for Precision Engineering 2018 International Journal of Precision Engineering and Vol.19 No.3

In this work, a series of burst tests and structural analyses have been carried out to demonstrate that, in terms of failure mode, Type 4 composite cylinder is saferwith a dome designed according to the isotensoid dome theory.In the test series, three sample vessels were used: (1) designed as guided by the isotensoid dome theory (called iso-dome cylinder); (2) with dome longer compared to uniform-stress design (called prolate cylinder); and (3) with dome wider than uniform-stress design (called oblate cylinder). Structural analyses have been performed using ABAQUS finite element code based on the periodic symmetry to circumferential direction. As a result, the maximum stresses are induced around the bodies of all three cylinders. However, the analyses, with the assumption of possible defect demonstrate that the maximum stresses are induced around the dome knuckles for the prolate and the oblate cylinders. The results of the ambient hydraulic burst tests for the three cylinders, conducted in compliance with KGS AC411-2015, show that the burst initiates from the cylinder body of the iso-dome cylinder and from the dome knuckles of the prolate and the oblate cylinders. Finally, it is recommended that, to comply with DOT CFFC 2007, the dome shape should be designed and fabricated as guided by the isotensoid dome theory.