• 대한용접접합학회:학술대회논문집
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• 대한용접접합학회 2002년도 Proceedings of the International Welding/Joining Conference-Korea
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• pp.133-138
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• 2002

Microbiologically Influenced Corrosion (MIC) was suspected in a corrosion failure of cooling system of stainless piping welded joint, carrying marine water. Marine water which is used for cooling water in a plant was transferred to the laboratory and used for experiment. In the first experiment, weld metal samples were exposed to the test solution for 56 days (marine water and sterilized marine water (control)). Surface condition of experimental coupons was observed using a Scanning Electron Microscope (SEM). In another experiment, free corrosion potential of these material was monitored for 56 days. Pitting corrosion was found in the coupons exposed to marine water. Free corrosion potential ennoblement was found to be significant compared to control. It was suspected that this corrosion case was MIC. In the second experiment, coupons were exposed to diluted nutrient medium containing single culture of microbes isolated from the MIC causing marine water sample used for the first experiment. After exposure test, surface condition of experimental coupon was observed using SEM. Pitting corrosion was found in coupons exposed to some of the isolates. The results indicate that they contribute to the corrosive effect of the SUS316L welds.

• Journal of Biosystems Engineering
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• 제8권2호
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• pp.62-68
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• 1983

This study was to examine the drying characteristics of barley and the effect of moisture content of barley on milling performance. A barley variety, Jogang, having 35.0% of initial moisture content was used for this experiment. Thermo-hydrostatic dryer which consists of blower, condensor, heater, humidifier, drying chamber and control box, etc., was used for the drying experiment. The change in the weight of a barley sample was continuously measured by means of the ring type load cell installed inside the drying chamber. Milling test runs the samples having the predetermined moisture content were taken from each drying test run. A laboratory type barley miller was used for the milling test. The results of the study are summarized as follows: 1. The drying constants (k) applied for the thin layer drying model, (M-Me)/(Mo-Me) = $Ae^{-kt}$ were 0.155, 0.259 and 0.548, respectively, at the three levels of drying temperatures, $40^{\circ}C$, $50^{\circ}C$ and $60^{\circ}C$. The drying constants complied with the Arrhenius Equation, K = Ko exp (-C/T), were determined as $Ko=1.901455{\times}10^8$ and C = 6563. 2. The laboratory milling test indicated that the highest milled and head barley recovery was resulted from the sample which was dryed at $40^{\circ}C$. In general, the increase in the drying temperature from $40^{\circ}C$ to $60^{\circ}C$ indicated a negative effect on milling yields. 3. Also, the sample having 15% M.C. presented the highest milled and head barley recovery among the five moisture content levels (12, 15, 18,21 and 24%).

• 한국산학기술학회논문지
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• 제16권8호
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• pp.5343-5350
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• 2015

본 연구의 목적은 대나무 줄기표면에서 처음 발견 하였으나, 아직까지는 연구가 미흡한 신 균주 Bacillus amyloliquefaciens NBF11-1의 생리활성 효과를 알아보기 위하여 청국장 전통 발효 균주인 Bacillus subtilis NG24를 대조군으로 하여 항산화효과에 대한 비교분석을 실시하였다. 청국장 추출물의 항산화 실험 결과에서 Total Polyphenol 추출물 함량의 측정 결과는 B.subtilis NG24에 비해 B.amyloliquefaciens NBF11-1 시료에서 유의하게 증가하였다(p=0.032). SOD 유사활성과 DPPH radical 소거능 및 NO radical 소거능에서 B.subtilis NG24에 비해 B.amyloliquefaciens NBF11-1을 포함한 시료에서 농도가 증가함에 따라 유의하게 증가하였다(p<.05). 추가적으로, 각 항산화 실험의 $IC_{50}$은 B.subtilis NG24에 비해 B.amyloliquefaciens NBF11-1 시료에서 SOD 유사활성(p=0.045), DPPH radical 소거능(p=0.041), NO radical 소거능(p=0.019)과 같이 유의한 차이로 감소하였다.

• 한국기후변화학회지
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• 제7권4호
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• pp.477-484
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• 2016

In general, $CH_4$ concentrations generated in combustion facilities are known to be ppm units. In most cases, $CH_4$ samples are collected in Tedlar bags and transported to laboratories for analysis. Considering this fact, in the present study, an attempt was made to find out how long samples can be stored in cases where they are kept in bags and transported as a preliminary study for sampling. According to the results of the experiment using simulated gases (1 ppm, 5 ppm, 10 ppm) in Tedlar bag, $CH_4$ was safe up to 240 hr which is the full time. In the case of simulated gases are containing 4 kind gases ($N_2$, $CO_2$, $CH_4$, and $N_2O$). Field samples (samples of obtained by collecting combustion facilities' exhaust gases) are known to contain highly reactive substances (for example NOx, SOx, and VOCs) and may affect each other. In the present study, one site sample was secured from each of a bituminous coal combustion facility and an LNG combustion facility and whether the concentrations of $CH_4$ gas would change over time (24 hr, 96 hr, 144 hr, 192 hr) was checked. Since site samples could not be analyzed on the day of collection, an experiment was started 24 hr after the time point of sampling to analyze the samples. As with the results of analysis of the simulated gas (240 hr), the results of analysis using the site sample indicated that it could be stored for the full study period 192 hr. Therefore, it was judged that if 192 hr would be taken after sampling before the sample would be analyzed, the concentration value should be reliable.

• 터널과지하공간
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• 제33권2호
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• pp.83-94
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• 2023

원통형 시료의 측면에 일정하게 구속압이 적용되는 통상적인 삼축시험 셀과는 달리, GREAT 셀은 독립적으로 제어되는 8쌍의 측면 가압장치들을 이용하여 차등적으로 구속압을 가할 수 있고, 이를 통해 다양한 크기와 방향의 수평 응력장을 생성시킬 수 있다. 본 연구의 선행 논문에서는 다양한 역학적 재하 조건에서 GREAT 셀 시험을 수치해석적으로 모사하고, 원주변형률에 대한 수치해석 및 실험측정 결과를 비교하여 적용된 수치모델의 적정성을 분석하였다. 본 연구에서는 역학적 재하 조건과 유체흐름 조건을 함께 고려하여 균열이 포함된 인공시료에 대한 GREAT 셀 시험을 수치모사하였다. 값이 알려지지 않은 균열면의 역학적 물성을 다양하게 설정하여 시료의 거동(원주변형률)에 대한 수치해석과 실험 결과를 비교하였으며, 균열면의 특정 역학적 조건에서 실험결과와 잘 일치하는 것으로 검토되었다. 추가적으로 유체흐름 조건이 시료의 역학적 거동에 미치는 영향을 분석하였다.

• 한국수학교육학회지시리즈A:수학교육
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• 제61권1호
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• pp.29-45
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• 2022

본 연구는 우리나라 초등학교 수학과 교육과정에서 가능성 지도가 우연(chance)과 무작위성(randomness)의 개념과 관련하여 어떻게 이루어지고 있는지 비판적으로 고찰하여 문제점을 분석하고자 한다. 이를 위해 먼저 우연과 무작위성 개념에 대해 살펴보고, 이를 바탕으로 우리나라 초등학교 수학에서 가능성 지도의 문제점을 제시하였다. 우리나라 초등학교 수학과 교육과정에서는 자료에 기반을 둔 추론의 경험이 결여되어 있었으며, 무작위성 지도가 적절히 이루어지지 않고 있었다. 또한 표본공간의 지도가 누락되면서 모순적인 소재가 활용되고 있었다. 마지막으로 가능성에 대한 지도가 특정 학년에 편중되어 지도되고 있음을 지적하였다. 확률 지도의 개선을 위해 크게 확률 실험의 지도와 표본공간의 지도를 제안하며, 또한 특정 학년에 편중된 구성을 위해 자료 영역의 내용을 조절할 것을 제안한다.

• 한국항해항만학회지
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• 제40권6호
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• pp.441-450
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• 2016

연안오염퇴적물에 함유된 유기물질과 PAHs의 현장정화를 위한 생물활성촉진제의 효능을 파일럿 규모의 현장실험을 통하여 1년간 평가하였다. 실험 해역의 수온은 계절적인 요인으로 인해 $16.5^{\circ}C$에서 $21^{\circ}C$까지 변화가 있었으나, 파일럿 반응조의 오염퇴적물의 pH는 8.4-8.5로서 비교적 일정하였다. 파일럿 실험종료 후 바탕시험구와 초산, 황산이온, 질산이온을 함유한 생물활성촉진제를 주입한 오염퇴적물의 화학적 산소요구량은 각각 39% 및 79%까지 감소하였으며, 휘발성고형물은 초기 약 15 g/kg에서 7 g/kg 및 2.5 g/kg까지 각각 감소하였다. PAHs는 2- ,3- ,4- ,5-ring 과 6-ring 16PAHs를 평가하였으며, 생물활성촉진제를 주입한 오염퇴적물에서 2-ring 화합물인 나프탈렌은 실험시작 2개월 후 100%(바탕시험구의 감소율 55.6%)까지 감소되어 가장 빨랐고, 12개월 후 3-ring 및 4-ring PAHs의 감소율은 모두 100%(바탕시험구의 감소율 46%-100%)에 달하였다. 5-ring과 6-ring PAHs의 12개월 후의 감소율은 바탕시험구와 생물활성촉진제를 투여한 오염퇴적물에서 각각 26%-87% 및 77%-100%로 평가되었다. 연안오염퇴적물에 투입한 생물활성촉진제는 유기물질 및 난분해물질인 PAHs의 제거속도를 향상시킬 수 있는 것으로 평가되었다.

• Journal of Acupuncture Research
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• 제18권3호
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• pp.94-104
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• 2001

Objective : The objective of tihs study is to study the effects of anti-cancer, anti-metastasis and effects of immune-response of aqua-acupuncture with Cuscutae Semen infusion solution. Methods : We observed, in-vitro, the cytotoxicity and the effect on the expression of MMP-9 gene, and in-vivo, change of body weight, surviving number, MST, ILS, changes in amount of WBC, RBC, PLT, GOT, GPT, creatinine, glucose and LDH, number of Pulmonary colony. Results : 1. The effect on expression of MMP-9 gene was decreased in all the sample groups in B16-F10 cell line, and was decreased in Lane 1, 2, 3 in HT1080 cell, compared with control group. 2. BALB/c mice which was transpianted S-180 cancer cell line were inhibited significantly in weight increase, in all the sample groups, compared with control group. 3. The sample groups injected in vein with B16-F10 cancer cell line in C57BL/6 mice did'nt show significant change in the number of WBC, RBC, PLT. 4. In immune experiment, all the sample groups showed having more relevancy to the effect on splenic cell proliferation than normal groups. 5. $IFN-{\gamma}$ and $TNF-{\alpha}$ in cytokine-gene were increased in all the sample groups than control group. 6. In flow cytometry of spienic cell, the numbers of CD4+ cell, CD8+ cell and CD19+ cell in sample groups were increased than in control group. Conclusion : Above the results showed that aqua-acupuncture of Cuscutae Semen infusion solution has effects of anti-cancer, anti-metastasis and immune response improvement.

• 동의신경정신과학회지
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• 제2권1호
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• pp.51-69
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• 1991

This experiment was conducted to study anti-stress effects of Guibiondamtang on several measures of stress, which were number of lever pressing, weight changes, water intake and gastroduodenal ulcer. The following results were observed: 1. There were no significant differences between the control group and the sample group in total number of lever pressing. And no significant differences were observed in the shock duration and the shock length. 2. The median water intake during the stress was 25ml for the sample group and 17ml for the control group and the difference was not statistically significant. 3. The median body weight losess after the psychological stress was given were 28g for the sample group and 35g for the control group and the difference was not statistically significant. 4. The mean frequencies of gastric ulcers induced by the psychological stress were 0.3 for the sample group and 2.3 for the control group and the difference was statistically significant. 5. The mean lengths of gastric ulcers induced by the psychological stress were 0.3mm for the sample group and 2.8mm for the control group and the difference was statistically significant. 6. The mean ratings of gastric ulcers induced by the psychological stress were 0.7 for the sample group and 1.9 for the control group and the difference was stastically significant. Thus it may be concluded that Guibiondamtang has an antistress effect.

• 한국연초학회지
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• 제16권2호
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• pp.163-171
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• 1994

This experiment was conducted to investigate the discrimination of cigarette brands and the similarity between Korea and America cigarette brands by near infrared spectra. Statistical tools such as principal component analysis (PCA) and mahalanobis distance(M.D) were used. The discrimination rate of the Korea and the America cigarette brands, determined by position number which was calculated with PCA and M.D, was 94% and 87%, respectively. The spectra of the 10 America cigarette brands were selected by averaging 5 sample spectra for each brand and another 5 spectra for each brand were investigated to use as the sample spectra. Comparing the sample spectra with the selected spectra by M.D using 410-1090 nm, 1110-1850 nm and 1970-2490 nm wavelength, the discrimination rate which was determined by the closest M.D between the sample and the selected spectra was 100% when each spectra was investigated on the same time. But the discrimination rate decreased 50% when the sample and the selected spectra were investigated on the different time. Excluding 1970-2490 nm wavelength, the discrimination rate increased up to 90% when the sample and the selected spectra were investigated on the different time. Comparing the spectra of Korea cigarette brands with those of America cigarette brands by M.D using only 410-1090 nm and 1110-1850 nm wavelength, the spectra of Expo(G) was similar to Winston, Vantage(U.L) and Benson & hedges(M.), the spectra of Hanaro(D) was similar to Carrel, Winston(L), Vantage(U.L), \Vantage and Carrel(L), the spectra of Hanaro(L) was similar to Winston(L) , Carton, Vantage and Carmel(L) and the spectra of Pinetree was similar to Kent, Kool, Kent(G.L), Merit and Benson & hedges(L), respectively. Key Words : NIRS, cigarette brands discrimination