• 한국환경농학회지
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• 제15권4호
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• pp.434-441
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• 1996

저장중인 사과에 발생하는 병해를 방지하기 위하여 postharvest 약제로서 benomyl과 bitertanol을 사과에 처리한 후 CA 및 저온저장시켜 저장중 약제의 분해양상, 잔류량의 변화 및 약제의 안전성 평가 그리고 약제의 사과 내로의 침투율을 조사하였다. CA저장에서 약제의 분해양상은 사과의 저장 초기에는 느린 속도로 분해되나 저장 후반기로 갈수록 빠르게 분해되며, 저온저장에서는 이와는 반대로 저장 후기보다 초기에 빠른 분해양상이 나타났다. Benomyl과 bitertanol이 표준살포농도로 처리된 사과에서의 초기농도는 2.24 및 1.54mg/kg으로 나타났으며, CA저장에서는 저장후 135 및 96일, 저온저장에서는 115 및 70일에 MRL인 1mg/kg에 이르렀다. Benomyl과 bitertanol의 분해반감기는 CA저장에서 124 및 130일이고, 저온저장에서는 101 및 111일로 나타나서 CA저장보다는 저온저장에서 보다 더 빠른 분해가 이루어졌다. Benomyl과 bitertanol이 처리된 사과에서의 침투율을 조사한 결과 두 약제 모두 과육부보다는 과피에 주로 잔류되어 있었다.

• Ocean Science Journal
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• 제42권4호
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• pp.223-230
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• 2007

To understand the origin and biogeochemistry of the organic matter in surface sediments of Lake Shihwa and Lake Hwaong, organic nitrogen, inorganic nitrogen, labile organic carbon, and residual organic carbon contents as well as stable isotope ratios for carbon and nitrogen were determined by KOBr-KOH treatment. Ratios of organic carbon to organic nitrogen $(C_{org}/N_{org})$ (mean = 24) were much higher than ratios of organic carbon to total nitrogen $(C_{org}/N_{tot})$ (mean= 12), indicating the presence of significant amounts of inorganic nitrogen in the surface sediments of both lakes. Stable isotope ratios for organic nitrogen were, on average, $5.2\%_{\circ}$ heavier than ratios of inorganic nitrogen in Lake Shihwa, but those same ratios were comparable in Lake Hwaong. This might be due to differences in the origin or the degree of degradation of sedimentary organic matter between the two lakes. In addition, stable isotope ratios for labile organic carbon were, on average, $1.4\%_{\circ}$ heavier than those for residual organic carbon, reflecting the preferential oxidation of $^{13}C$-enriched organic matter. The present study demonstrates that KOBr-KOH treatment of sedimentary organic matter can provide valuable information for understanding the origin and degradation state of organic matter in marine and brackish sediments. This also suggests that the ratio of $(C_{org}/N_{org})$ and stable isotope ratios for organic nitrogen can be used as indexes of the degree of degradation of organic matter.

• 공업화학
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• 제29권2호
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• pp.248-251
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• 2018

고정층 반응기와 파이롤라이저-가스크로마토그래피/질량분석기를 이용하여 커피 잔류물이 함유된 폐종이컵의 열분해 및 촉매 열분해를 진행하였다. 커피 잔류물이 함유된 종이컵의 무촉매 열분해에서는 많은 양의 오일이 가스 및 촤와 함께 형성되었다. HZSM-5와 HY 촉매의 사용에 따른 추가적인 분해 반응에 의해 오일의 양은 줄고 가스의 양은 증가하였다. HZSM-5와 HY의 산촉매 특성 때문에 커피 잔류물이 함유된 종이컵의 촉매 파이롤라이저-가스크로마토그래피/질량분석기 분석은 생성오일 중 방향족 화합물의 선택도를 증가시켰다. HY보다 강한 산세기와 중간 기공을 가진 HZSM-5의 특성으로 인해, HZSM-5상에서 커피 잔류물이 함유된 종이컵을 촉매 열분해한 경우 HY를 사용한 경우보다 휠씬 더 많은 양의 방향족 화합물이 생성되었다.

• 한국대기환경학회지
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• 제27권6호
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• pp.650-662
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• 2011

The statistical tools such as empirical orthogonal function (EOF), and singular value decomposition (SVD) have been applied to analyze the characteristic of air pollutant over southeast Asia as well as to evaluate Zimeke's tropospheric column ozone (ZTO) determined by tropospheric residual method. In this study, we found that the EOF and SVD analyses are useful methods to extract the most significant temporal and spatial pattern from enormous amounts of satellite data. The EOF analyses with OMI $NO_2$ and OMI HCHO over southeast Asia revealed that the spatial pattern showed high correlation with fire count (r=0.8) and the EOF analysis of CO (r=0.7). This suggests that biomass burning influences a major seasonal variability on $NO_2$ and HCHO over this region. The EOF analysis of ZTO has indicated that the location of maximum ZTO was considerably shifted westward from the location of maximum of fire count and maximum month of ZTO occurred a month later than maximum month (March) of $NO_2$, HCHO and CO. For further analyses, we have performed the SVD analyses between ZTO and ozone precursor to examine their correlation and to check temporal and spatial consistency between two variables. The spatial pattern of ZTO showed latitudinal gradient that could result from latitudinal gradient of stratospheric ozone and temporal maximum of ZTO in March appears to be associated with stratospheric ozone variability that shows maximum in March. These results suggest that there are some sources of error in the tropospheric residual method associated with cloud height error, low efficiency of tropospheric ozone, and low accuracy in lower stratospheric ozone.

• 대한핵의학회지
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• 제26권2호
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• pp.355-359
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• 1992

The $^{67}Ga$ has somewhat long physical and biological half livies with 78 hours and 600 hours respectively, so we can get $^{67}Ga-scan$ images for 3 or more days after once injection of $^{67}Ga$. Furthermore $^{67}Ga$ scan would be useful to search some residual tumors after surgical removal of the tumors trapped with $^{67}Ga$. However $^{67}Ga$ bound with plasma proteins would be delayed in plasma clearance as approximately 10% of the dose remains in the plasma at 24 hours. If the remained $^{67}Ga$ in the plasma is redistributed into the surgical wound, we wouldn't evaluate the degree of the tumor remained after surgery. So the authors examined the amounts of the remained blood $^{67}Ga$ and the redistribution of the blood $^{67}Ga$ into the artificial wound with S or more centimeters in the diameter at the neck and chest of the rabbits. The results were as follows; 1) The $^{67}Ga$ remained in the plasma were 12%, 5.7%, 4.2% at 24, 48 and 72 hours after $^{67}Ga$ injection respectively. 2) The blood $^{67}Ga$ were redistributed into the artificial wound with 5.9% at 48 hours and 6.9% at 72 hours after $^{67}Ga$ injection.

• Food Science and Biotechnology
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• 제16권6호
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• pp.868-872
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• 2007

The microbiological and chemical identification of antibiotic residues was attempted for livestock and seafood products including pork (n=34), beef (n=34), chicken (n=32), flatfish (n=37), armorclad rockfish (n=36), and sea bream (n=27). The meat (n=100) and seafood (n=100) samples were collected from 9 markets in 5 major Korean cities. Antibiotic substances were identified from the classes of tetracyclines, macrolides, penicillins, aminoglycosides, polyethers, peptides, sulfonamides, quinolones, chlorampenicols, and novobiocins using a microbiological assay, the Charm II test and high performance liquid chromatography (HPLC) with ultra violet (UV) and fluorescence detectors. The results showed that 2 tetracyclines (oxytetracycline and tetracycline) and 3 quinolones (ciprofloxacin, norfloxacin, and enrofloxacin) were detected in 4 samples of flatfish among all 100 seafood samples tested. No antibiotic residues were detected in the 100 livestock product samples tested. The amounts (min-max, mg/kg) of the residual antibiotics were as follows; tetracycline 0.78-0.85, oxytetracycline 0.49-0.74, ciprofloxacin 0.09-0.83, norfloxacin 0.01-0.21, enrofloxacin 0.12-2.98. These data indicate that the total detection rate of antibiotics in livestock and seafood products was approximately 2%.

• 한국환경농학회지
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• 제40권2호
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• pp.118-126
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• 2021

BACKGROUND: It is very important to monitor the residual characteristics of pesticides in pre-harvest fresh ginseng to ensure consumer safety. METHODS AND RESULTS: Forty-eight fresh ginseng samples were collected from 8 ginseng-growing fields 10 days before harvest and pesticide residues in fresh ginseng with and without rhizome (head of ginseng) and rhizome were analyzed for 320 pesticides by using GC-MS/MS and LC-MS/MS. As a result of the pesticide residue analysis, the number of pesticides detected from the fresh ginseng with rhizome, that without rhizome and rhizome were 26, 25, and 40, respectively, indicating that high number of pesticides found in rhizome, compared with the other parts. Pyraclostrobin was detected with the highest frequency in all samples, reaching to 21.2% in fresh ginseng with rhizome, 16.8% in that without rhizome, and 14.8% in rhizome. CONCLUSION: The residue levels of pesticides detected did not exceed their maximum residue limits, in spite of residual data in fresh ginseng before harvest. The amounts of the estimated daily intakes of all the detected pesticides were found to be from 0.018 to 1.818% of their acceptable daily intakes, indicating that concentrations of pesticides detected from fresh ginseng with and without rhizome collected before harvest do not pose the immediate health risks.

• 한국해안·해양공학회논문집
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• 제32권3호
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• pp.147-160
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• 2020

추계학적 WP을 이용하여 불확실성을 고려하면서 항만 구조물의 실시간에 따른 피해와 파괴확률 그리고 잔류수명을 해석할 수 있는 모형을 수립하였다. 과거부터 현재까지의 피해상태와 미래에 발생될 피해 진행 과정에 포함되는 불확실성을 고려할 수 있는 추계학적 확률모형이다. 피해경로를 추적할 수 있으며 누적피해의 밀도함수도 산정하여 파괴확률을 추정할 수 있다. 또한 구조물의 잔류수명에 대한 밀도함수도 구할 수 있다. 최소자승법과 최우도법을 이용하여 모형의 파라미터를 추정할 수 있는 방법도 제시하였다. 검증을 위해 시간의 진행에 따른 누적피해와 잔류수명에 대한 밀도함수를 산정하고 해석하였는데 이론적인 결과가 MCS 기법의 수치적인 결과와 매우 잘 일치하였다. 또한 내구수명이나 잔류수명에 대한 밀도함수의 거동과 MTTF와 MRL이 정량적으로 잘 일치하였다. 한편 본 연구에 수립된 모형을 경사제에 적용하기 위하여 피복재 피해에 대한 수리모형 실험자료를 활용하여 모형의 파라미터들을 추정하였다. 시간의 진행에 따른 피복재 누적피해의 밀도함수와 파괴확률을 산정하였는데 MCS의 결과와 이론적인 결과가 매우 잘 일치하였다. 경과시간이 클수록 밀도함수가 우측으로 이동하면서 불확실성이 커지면서 파괴확률이 급격하게 증가하였다. 또한 재령에 따른 잔류수명의 거동특성을 해석하였는데, 잔류수명의 분포함수에서 좌측보다는 우측 꼬리 부분이 길게 형성되어 MRL이 급격하게 감소하는 경향을 보였다. 이는 경사제 피복재의 피해가 완만하게 증가하는 현상을 반영한 것으로 판단된다. 특히 재령과 내구수명 그리고 잔류수명의 관계를 해석하였는데, 재령이 오래될수록 재령과 MRL의 합이 MTTF와 큰 차이를 보이고 있다. 이는 재령이 증가하면 잔류수명의 평균인 MRL이 불확실성에 의하여 급격히 감소하기 때문이다.

• Toxicological Research
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• 제24권1호
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• pp.87-91
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• 2008

The present study was conducted to monitor the level of triflumizole residues in fruits (apple and pear) and vegetable (cucumber) samples in order to assess risk posed by the presence of such residues to the consumer. Triflumizole was applied at a recommended dose rate to apple and pear pulps and to a cucumber sample. The samples were collected at harvesting time following several treatments (three and/or four treatments). Triflumizole was extracted with methanol and re-extracted into dichloromethane. The presence of triflumizole was determined by HPLC with UV detection at 238 nm following the cleanup of the extract by open preparative chromatographic column with Florisil. The versatility of this method was evidenced by its excellent linearity (> 0.999) in the concentration range between 0.2 and 4.0 mg/kg. The mean recoveries evaluated from the untreated samples spiked at two different fortification levels. 0.1 and 0.4 mg/kg, and ranged from 87.5${\pm}$0.0 to 93.3${\pm}$2.6 for the tested fruits and vegetable, respectively, and the repeatability (as relative standard deviation) from three repetitive determinations of recoveries were no larger than 6%. The calculated limit of detection was 0.02 mg/kg and the minimum detectable level of 4 ng for triflumizole was easily detected. When triflumizole was sprayed onto the apple trees three times at 50-40-30 and 40-30-21 days prior to harvesting and four times onto the pear trees at 40-30-21-14 days prior to harvesting, the mean residual amounts of 0.05 and 0.06 mg/kg for apples and pears, respectively, were not detected in all of the treatments. When the cucumber sample was fumigated four times at 7, 5, 3 and 1 day prior to harvesting, the mean residual amount was not detectable. Triflumizole can be used safely when sprayed (wettable powder, 30% active ingredient) and fumigated (10%) 4 times at 14 and 1 day prior to harvesting to protect the fruits and vegetable, respectively.

• 대한환경공학회지
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• 제35권5호
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• pp.350-355
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• 2013

본 연구는 음료용 자동판매기의 냉매인 HFC-134a의 사용 및 폐기단계 탈루배출특성을 파악코자 하는데 그 목적을 두고 있다. 국내 제품인 음료용 폐자동판매기 47대의 HFC-134a 냉매를 상업용 냉매 회수기를 사용 회수하였고, 잔류량을 측정하였다. 본 연구에서 개발한 사용단계 탈루배출모델은 1차 동역학에 기초한 것으로 탈루율은 잔류 냉매 압력 즉 잔류량에 비례한다는 가정을 도입 적용하였다. 음료용 폐자동판매기의 배출시점에서의 잔류량과 사용기간 정보를 활용하여 탈루배출계수를 간접적으로 $6.9{\pm}0.7$ %/yr으로 결정하였고 이는 1대당 연간 11.6 g의 HFC-134a가 배출되는 것에 해당된다. 한편 음료용 폐자동판매기 냉매 평균 잔류율은 $62.5{\pm}2.2%$이었으며, 이는 1대당 잠재 탈루량을 144.8 g으로 결정할 수 있다. 음료용 자동판매기에서 회수한 폐냉매 성분 분석 결과가 신냉매와 거의 유사하여 폐냉매의 재사용이 가능할 것으로 여겨진다. 그러나 냉매회수 과정에서 압축기 오일이 30% 정도 포함되기 때문에 냉매 재사용을 위해서는 오일 분리가 필요하다.