수분산 폴리우레탄의 사슬연장 반응에 관한 연구

공현철,정인우,김중현 한국공업화학회 2003 응용화학 Vol.7 No.1

In the synthesis of water-based polyurethane using self-emulsification process, afterbeing neutralized polyurethane pre=polymers containing ionic pendant groups are dispersed by simple convective mixing Preparation of dispersion is followed by chain extension reaction, which is considered as important step for growth of the molecular weight of polyurethane, In this work pH variations in the aqueous phasa were monitored during the chain extension process in the presence of water-soluble diamines. The optimum degree of chain extension and the average prrticle size in the polyurethane dispersions were examined with varying ionic pendent group contents, type of chain extenders, and feed reat of chain extenders.The initial pH value in the aqueous phase linearly increased andthe optimum chain extension point could be obtained from the intersection of two linear lines having different slopes. All averge particle sizes before chain extension reaction were almost same, howeve,the final averge particle size increased as feed rates of chain extenders incerased. In addition as the ionic pendant group contents increased, the particle size decreased since the hydrophilicity and hydrodynamic volume increased. As carbon numbers of the chain extenders inreased, the final particle size increased significantly From the results it was concluded that the chain extension reaction took place among the particles not only in a particle.

중금속에 오염된 고형시료의 직접 급성독성 측정

공인철,Bitton, Gabriel 嶺南大學校 環境問題硏究所 1995 環境硏究 Vol.14 No.2

고형시료의 독성 측정시 다량의 추출용매에 희석된 추출물을 이용하지 않고, 적은 양의 용매(1㎖)를 고형시료에 직접 이용하는 급성독성 실험법이 개발되었다. 독성은 유기오염물에 덜 민감하고 중금속에 민감한 효소(β-galactosidase)의 활동도로써 측정했다. β-galactosidas를 생산하는 변이성 E.coli strain을 포함한 1㎖의 용액과 고형시료 0.5 혹은 1.0g의 양이 사용되었다. 고형시료의 기질 색깔 흡수에 대한 변화와 시료에 원래 존재해 있는 효소의 활동은 control에 의해 감안되었고 사용된 용매중 0.1M sodium nitrate가 Milli-Q water보다는 약간 높은 민감도를 나타내었다. 여러종류의 고형시료를 사용한 결과 거주지나 상업지역보다는 공업지역에서 채취한 시료가 높은 독성치를 나타냈다. 독성측정의 결과를 고찰해 볼 때 오염된 동과 아연에 대해서는 독성치가 금속량에 비례하였다. 제안된 이 방법을 이용하여 고형환경의 오염을 이용하게 screening 할 수 있다고 판단되며, 또한 고형시료 오염원의 주(主)원인(중금속 혹은 유기오염물)을 판별하는데는 유효한 방법이 되리라 사료한다. A direct toxicity assay for soils, sediments and sludges which is specific for heavy metal toxicity was developed. In the assay, extraction of metals from the solids sample is not required. Use of 0.1 M sodium nitrate as eluent was found to yield somewhat higher sensitivy to heavy metal in solid phase smaples than Milli-Q water. Application of the assay to a diverse array of soils, sludges and sediments illustrated that samples from industrial sites were generally more toxic than those from residential or commercial sites. Heavy metal toxicity was correlated with the copper and zinc content of solid samples, but toxicity varied considerably at the lower range of metal contents. Proposed solid phase assay should be useful as a screening test for heavy metal toxicity in solids environments.

복숭아의 PCR 최적 조건 구명

공현정,박진철,김성만,김용철,이충열,박현철,최인수 밀양대학교 농업기술개발연구소 2000 農業技術開發硏究所報 Vol.4 No.1

To optimize PCR condition is the most important and fundamental step for experiments using PCR. The purpose of this study was to optimize PCR condition for RAPD analysis in peach. 3×3×3 factorial experiment for template DNA concentration, MgCl2 concentration, and amount of taq polymerase was conducted. Another factorial experiment for denature, annealing, extension temperature on the optimal PCR condition was also conducted. The best template DNA concentration was 20ng(0.5unit taq polymerase and 2.5mM MgCl2), 40ng(0.5unit taq polymerase and 4.5mM MgCl2, and 1unit taq polymerase and 2.5mM MgCl2), and 60ng(0.5unit taq polymerase and 2.5mM MgCl2, 0.5unit taq polymerase and 4.5mM MgCl2, 1unit taq polymerase and 2.5mM MgCl2, 1unit taq polymerase and 4.5mM MgCl2, and 1unit taq polymerase and 7.0mM MgCl2). The best MgCl2 concentration was 2.5mM(40ng template DNA and 1unit taq polymerase, 60ng template DNA and 0.5unit taq polymerase, and 60ng template DNA and 1unit taq Folymerase), and 4.5mM(40ng template DNA and 0.5unit taq polymerase, 40ng template DNA and 1unit taq polymerase, 60ng template DNA and 0.5unit taq polymerase, and 60ng template DNA and 1unit taq polymerase), and 7.0mM (60ng template DNA and 1unit taq polymerase). The best taq polymerase concentration was 0.5unit(20ng template DNA and 2.5mM MgCl2, 40ng template DNA and 4.5mM MgCl2, 60ng template DNA and 2.5mM MgCl2, and 60ng template DNA and 4.5mM MgCl2), and 1unit(40ng template DNA and 2.5mM MgCl2, 60ng template DNA and 2.5mM MgCl2, 60ng template DNA and 4.5mM MgCl2, and 60ng template DNA and 7.0mM MgCl2). When we consider results from template DNA concentration, MgCl2 concentration, and amount of taq polymerase, 5 conditions(60ng of template DNA, 7.0mM MgCl2 and 1unit taq polymerase; 60ng of template DNA, 4.5mM MgCl2 and 1unit taq polymerase; 60ng of template DNA, 2.5mM MgCl2 and 0.5unit taq polymerase; 40ng of template DNA, 2.5mM MgCl2 and 1unit taq polymerase; and 40ng of template DNA, 4.5mM MgCl2 and 0.5unit taq polymerase;) were best combinations for the optimal PCR condition. Reaction temperatures for the optimal PCR condition were 90℃, 40℃, 72℃ and 92℃, 36℃, 72℃.

한국인 직무 스트레스 측정도구의 개발 및 표준화

장세진,고상백,강동묵,김성아,강명근,이철갑,정진주,조정진,손미아,채창호,김정원,김정일,김형수,노상철,박재범,우종민,김수영,김정연,하미나,박정선,이경용,김형렬,공정옥,김인아,김정수,박준호,현숙정,손동국 大韓産業醫學會 2005 대한직업환경의학회지 Vol.17 No.4

Background and Purposes: Over the past three decades, numerous studies performed in Korea have reported that job stress is a determinant risk factor for chronic diseases and work disability. Every society has its own culture and occupational climate particular to their organizations, and hence experiences different occupational stress. An occupational stress measurement tool therefore needs to be developed to estimate it objectively. The purpose of this study is to develop and standardize the Korean Occupational Stress Scale (KOSS) which is considered to be unique and specific occupational stressors in Korean employees. Subjects and Methods: Data were obtained from the National Study for Development and Standardization of Occupational Stress (NSDSOS Project: 2002-2004). A total of 12,631 employees from a nationwide sample proportional to the Korean Standard Industrial Classification and the Korean Standard Occupational Classification were administered. The KOSS was developed for 2 years (2002-2004). In the first year, we collected 255 items from the most popular job stress measurement tools such as JCQ, ERI, NIOSH and OSI, and 44 items derived from the a qualitative study (depth interview). Forty-three items of KOSS, in the second year, were retained for use in the final version of the KOSS by using Delphi and factor analysis. Items were scored using conventional 1-2-3-4 Likert scores for the response categories. Results: We developed eight subscales by using factor analysis and validation process: physical environment (3 items), job demand (8 items), insufficient job control (5 items), interpersonal conflict (4 items), job insecurity (6 items), organizational system (7 items), lack of reward (6 items), and occupational climate (4 items). Together they explained 50.0% of total variance. Internal consistency alpha scores were ranged from 0.51 to 0.82. Twenty-four items of the short form of the KOSS (KOSS-SF) were also developed to estimate job stress in the work setting. Because the levels of the subscales of occupational stress were gender dependent, gender-specific standard norms for both the 43-item full version and the 24-item short form using a quartile for the subscales of KOSS were presented. Conclusion: The results of this study suggest that KOSS might be an appropriate measurement scale to estimate occupational stress of Korean employees. Further and more detailed study needs to be conducted to improve the validity of this scale.

참외의 PCR 최적 조건 구명

공현정,김용철,최인수 밀양대학교 농업기술개발연구소 2000 農業技術開發硏究所報 Vol.4 No.1

This study was conducted to identify the optimized PCR condition in cucumis melo. Factorial experiments for template DNA concentration, MgCl2 concentration, amount of taq polymerase, and reaction temperature(denature, annealing, extension) were conducted. The best template DNA concentration was 40ng(0.5unit taq polymerase and 4.5mM MgCl2, and 1unit taq polymerase and 2.5mM MgCl2), 60ng(0.5unit taq polymerase and 2.5mM MgCl2, 0.5unit taq polymerase and 4.5mM MgCl2, 1unit taq polymerase and 2.5mM MgCl2, 1unit taq polymerase and 4.5mM MgCl2, and 1unit taq polymerase and 7.0mM MgCl2). The best MgCl2 concentration was 2.5mM(40ng template DNA and 1unit taq polymerase, 60ng template DNA and 0.5unit taq polymerase, and 60ng template DNA and 1unit taq polymerase)와 4.5mM(40ng template DNA and 0.5unit taq polymerase, 60ng template DNA and 0.5unit taq polymerase, and 60ng template DNA and 1unit taq polymerase), and 7.0mM(60ng template DNA and 1unit taq polymerase). The best amount of taq polymerase was 0.5unit(40ng template DNA and 4.5mM MgCl2, 60ng template DNA and 2.5mM MgCl2, and 60ng template DNA and 4.5mM MgCl2) and 1unit(40ng template DNA and 2.5mM MgCl2, 40ng template DNA and 4.5mM MgCl2, 40ng template DNA and 7.0mM MgCl2, 60ng template DNA and 2.5mM MgCl2, 60ng template DNA and 4.5mM MgCl2, and 60ng template DNA and 7.0mM MgCl2). When we consider results from template DNA concentration, MgCl2 concentration, and amount of taq polymerase, 6 conditions(60ng template DNA, 7.0mM MgCl2, 1unit taq polymerase; 60ng template DNA, 4.5mM MgCl2, 1unit taq polymerase; 60ng template DNA, 2.5mM MgCl2, 1unit taq polymerase; 60ng template DNA, 4.5mM MgCl2, 0.5unit taq polymerase; 60ng template DNA, 2.5mM MgCl2, 0.5unit taq polymerase; and 40ng template DNA, 2.5mM MgCl2, 1unit taq polymerase) were best combinations for the optimal PCR condition. Reaction temperatures for the optimal PCR condition were 90℃, 40℃, 72℃ and 92℃, 36℃, 72℃.

地盤 掘鑿時의 地盤앵커에 의한 近接 構造物의 沈下 抑制 效果

강낙안,공영주,주인곤,임종철 釜山大學校生産技術硏究所 1996 生産技術硏究所論文集 Vol.50 No.-

지하구조물의 건설을 위한 깊은 굴착으로 인해 근접구조물에 많은 피해가 발생하고 있다. 피해를 일으키는 주된 원인은 흙막이 벽체의 수평변위에 의한 지반침하와 지하수위 저하나 진동등에 의한 압밀, 다짐 발생에 따른 지반침하 등이다. 지금까지 대부분의 연구는 현장계측을 이용하였으므로, 벽체의 변위와 지반침하에 영향을 미치는 많은 인자들 각각의 영향을 밝히기는 대단히 어려웠다. 본 연구에서는 실내 모형실험을 통하여 최종 굴착시의 주동파괴면 안쪽에 놓여있는 구조물의 침하를 최소화할 수 있는 지반앵커(1단, 2단)의 위치 및 간격을 결정하였다. 실험결과, 앵커 1단 설치, 앵커 2단 설치의 경우가 모두 앵커 깊이 비=0.4∼0.5일 때, 근접구조물의 침하가 최소가 되었다. 또, 지반 굴착시의 지반변형을 관찰하여 위의 사실을 확인하고, 지반 파괴면의 위치 및 형상을 구하였다. The structure is often deformed and damaged by deep excavation. This deformation and damage are mainly made by ground settlement(consolidation, compaction) owing to groundwater drop or vibration etc. and lateral movement of retaining wall. Then, most studies about deformation of ground have done by using results of site measurement, so it was very difficult to find each effect of many factors separately. The purpose of this study is to decide the location and interval of ground anchor( lst, 2nd ground anchor) to be able to minimize the settlement of adjacent structure located inside the active failure surface by model test at laboratory. As results of this model test, it was known that the depth ration of anchor to minimize the settlement of near-by structure was 0.4∼0.5, and by the observation of ground deformation during excavation, the direction and magnitude of displacement and the failure line could be known.

고정화한 유전자 재조합 균주 Pseudomonas putida mt-2 KG1206의 톨루엔 계열 화합물에 대한 생물발광 활성 조사

공인철(In Chul Kong),정홍경(Hong Kyung Jung),고경석(Kyung Seok Ko) 大韓環境工學會 2009 대한환경공학회지 Vol.31 No.2

본 연구에서는 톨루엔 계열 화합물로 오염된 환경에 대해 고정화한 유전자 재조합 균주 KG1206의 적용 가능성에 대해 조사하였다. 재조합 균주 KG1206은 직접 유도제인 m-toluate, benzoate 뿐만 아니라 톨루엔, 자일렌 이성질체가 간접 유도제로서 발광 활성을 나타낸다. 연구에 의해 결정된 고정화 프로토콜의 최적 조건은 다음과 같다: 균주 농도(1:1 (v/v)), 오염원 용액(인산염 완충액), 발광 측정에 필요한 비드 수(4개), 5가지 오염원에 대한 최대 발광 활성은 일반적으로 m-toluate>p-xylene>톨루엔>o-xylene>m-xylene 순으로 나타났다. 생물발광과 오염원 감소는 HPLC로 확인하였으며, 고정 균주에 의해 초기 5 mM m-toluate는 5시간 배양 후 약 48%의 감소율을 나타내었으며 계속 분해되는 경향이 관찰되었다. 알긴산 균주 고정화에 대한 본 연구 결과는 톨루엔 계열 화합물을 함유한 석유계 탄화수소에 오염된 특정 환경을 생물학적 모니터링에 유용한 방법으로 사용할 수 있을 것이다. In this study, the applicability of alginate-immobilized Pseudomonas putida mt-2 KG1206 on the environments, contaminated with toluene analogs was conducted. Genetically engineered strain KG1206 produces light by direct (m-toluate, benzoate) and indirect (toluene, xylenes) inducers. The protocol for the alginate-immobilization was determined in terms of the cell to alginate ratio, solution, proper number of alginate beads, and other conditions. Maximum bioluminescences of five chemicals by immobilized strain were generally observed in following orders: m-toluate>p-xylene>toluene>o-xylene>m-xylene. In relationship between bioluminescence activity and inducer reduction, initial m-toluate (5 mM) in solution was removed approximately 48% of initial at 5 h exposure, showing continuous decrease of inducer chemical in solution. These results of study with alginate-immobilized beads would be useful, especially, for biomonitoring of contaminated environments with specific compounds, such as petroleum hydrocarbon compounds including toluene analogs.

대청댐 저층 퇴적물 박테리아 군집과 활성 평가

공인철 ( In Chul Kong ),이용상 ( Yo Sang Lee ) 한국환경영향평가학회 2003 환경영향평가 Vol.12 No.1

Bacterial activities of dam reservior sediments were assssed using the methods of viable countes,ATP contents,dehydrogence a activity, and oxygen consumption.Viable heterorophs in collected sediments were observed in the range of 10^6∼10^10 CFU/g dry wt. sediments all assessed methods showed high activities in sediment samples collected from near dam site. In additionm bacteria increase in sediments amended wth cellulose, starch, lipid, and protein compounds, Various ranges of sediciotics and heavy metals resistance bateria were also detected, 10∼100 times less numbers of Cd resistance bacteria were also detedcted were observed compared with thodse of Pb and Cr.In general, antibionresistance grops were in the range of 10^-1∼10^_6 Tmes of cintrol.

A Pilot Study on the Muscle Activities in Step Input Test as an Indicator of the Vehicle Characteristics

Yong-Ku Kong,Myung-Chul Jung,In-Seok Lee,Young-Jin Hyun,Chang-Su Kim,Min-Tae Seo 대한인간공학회 2013 大韓人間工學會誌 Vol.32 No.3

Objective: The purpose of this study was to analyze "response time", "peak response time" and "overshoot value" for each muscle by applying the EMG signal to the vehicle response in ISO 7401 and to quantify the response of the driver according to vehicle characteristics by comparing vehicle characteristics and muscle responses of the driver. Background: The Open-loop test defined in international standards ISO 7401 is the only method for evaluating the performance of the vehicle. However, this test was focused only on mechanical responses, not driver"s ones. Method: One skilled male driver(22 yrs. experience) was participated in this experiment to measure muscle activities of the driver in transient state. Then the seven muscle signals were applied to calculate "response time", "peak response time", and "overshoot value". Results: In the analyses of the EMG data, the effects of vehicle type and muscle were statistically significant on the "response time" and "peak response time". Also, the effects of vehicle type, muscle, and lateral acceleration level were statistically significant on the "overshoot value" in this study. According to the analyses of the vehicle motion data, vehicle motion variable(LatAcc, Roll, YawVel) was statistically significant on the "response time" and vehicle type, vehicle motion variable, and lateral acceleration level were statistically significant on the "peak response time", respectively. Conclusion: In the analyses of the "response time" and "overshoot value", the data of muscle activities(EMGs) was better index that could evaluate the vehicle characteristic and performance than the data of vehicle motion. In case of peak response time, both EMG and vehicle motion data were good index. Application: The EMGs data from a driver might be applicable as index for evaluation of various vehicle performances based on this study.

Protective Effects of Silymarin against the Toxicity of Bisphenol A (BPA) on Boar Sperm Quality

Jang, Hyun-Young,Kong, Hong-Sik,Choi, Byoung-Yang,Shin, Jong-Suh,Cheong, Hee-Tae,Kim, Jong-Tack,Park, In-Chul,Park, Choon-Keun,Yang, Boo-Keun 韓國受精卵移植學會 2011 한국동물생명공학회지 Vol.26 No.4

BPA, a diphenyl compound containing groups, that make it structurally similar to synthetic estrogen and is considered as one of the major endocrine disruptors. Silymarin has extensively been used to prevent and/or alleviate some human disease, especially for the treatment of adverse liver conditions. It has an antioxidative efficacy and cancer preventive efficacy. Therefore, we examined the hypothesis that silymarin can inhibit BPA-induced toxicity in boar sperm duing in vitro storage. Sperm characteristics (motility, viability, membrane integrity and mitochondrion activity) in semen exposed to BPA (10~200 uM) were sharply lowered, while it increase in a dose and time dependent manner due to silymarin addition (50~200 uM) into semen extender in the presence of BPA (100 uM). All of the evaluated characteristics were gradually improved in the groups that were treated with silymarin (50~200 uM) in the presence of BPA (100 uM) in comparison to BPA 100 uM alone group, irrespective of incubation periods (3 and 6 h). These results demonstrate that silymarin can ameliorate the toxicity of BPA on boar sperm characteristics during in vitro storage, suggesting that silymarin indirectly act as an antioxidant.