• Applied Biological Chemistry
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• 제22권3호
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• pp.142-144
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• 1979

경기도(京畿道) 용인군(龍仁郡)과 화성군(華城郡)의 농촌지역(農村地域)에서 음료수(飮料水)를 취(取)하여 세균검사(細菌檢査)를 한 결과(結果)를 요약(要約)하면 다음과 같다. 1. 총생균수는 3지역의 시료만 100/ml이하였으며 $1{\times}10^4/ml$ 이상은 6지역이었으며 최고 $1{\times}10^5/ml$로 나타났다. 2. Faecal Streptococcus는 용인군(龍仁郡)의 4개 지역의 시료에서 검출(檢出)되었다. 3. 음료(飮料) 적합여부(適合如否)를 국립보건 연구원의 표준비교에 의하여 판정한 결과 할 지역의 시료를 제외한 모두가 음료(飮料) 부적(不適)내지 음료적합여부(飮料適合如否)가 의심스러운 것으로 밝혀졌다.

• 한국환경보건학회지
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• 제33권6호
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• pp.517-521
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• 2007

To assess possible risks from the consumption of drinking water from various sources, a survey of the microbiological quality of tap water, commercial bottled drinking water which is exploited from natural mineral water, and natural spring water was conducted. A total of 4 different brands of commercial bottled drinking water, and 4 types of spring water from different sources, and tap water from 4 private houses were tested for four index microorganisms, and the microbial quality changes of the water during the storage at room temperature or refrigerated temperature for 7 days. Aerobic plate counts of all of the initial water samples were still within 100 CFU/ml (drinking water standard of Korea). Total coliforms, fecal coliforms, and E. coli were not detected in all of the water samples at initial. However, aerobic plate counts of three types of spring water and three types of bottled drinking water stored at room temperature showed higher levels than the standards in 5 days. Total coliforms were detected in three types of spring water after one day's storage at room temperature, and in one type of bottled drinking water after 5 days' storage. These results indicate that some of the spring water surveyed are not safe to drink, and the spring water and bottled drinking water after opening the lid should not be stored at room temperature, if they are used for drinking.

• 한국물환경학회지
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• 제24권6호
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• pp.817-822
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• 2008

In order to identify various Cryptosporidium species in environment, nested PCR-RFLP and DNA sequencing method were used. The sensitivity of nested PCR-RFLP based on 18s rRNA gene was shown to 1 oocyst. Therefore, we applied nested PCR-RFLP method to environmental samples. As a result, only 4 samples out of 8 samples confirmed as Cryptosporidium parvum by standard method of Cryptosporidium were identified as Cryptosporidium parvum by nested PCR-RFLP and DNA sequencing method. The rest of 4 samples among 8 samples were identified as Cryptosporidium muris, Cryptosporidium bailey. Therefore, in addition to standard method of Cryptosporidium, supplementary verification through nested PCR-RFLP and DNA sequencing should be needed to give more accurate information about risk of Cryptosporidium.

• 한국조리학회지
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• 제23권4호
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• pp.105-115
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• 2017

Water is an essential ingredient to brew coffee. Mineral contents in the water can affect both water quality and taste quality of coffee. The effects of minerals in the water on sensory characteristics of coffee were investigated in different water samples (A: Arisu, B: Claris, C: Spring water, D: Samdasoo, E: Evian, Distilled water as control). Based on the results of quantitative descriptive analysis (QDA), there were statistically significant (p<0.01) in flavor, acidity, bitterness, sweetness, body and aftertaste according to different water samples used to brew coffee. The canonical correlation analysis of minerals (Ca, Mg, Na, K) and taste (acidity, bitterness, sweetness) indicated that there were highly correlated in the relationship between bitterness and Mg content. A strong negative relationship was shown between bitterness and acidity, sweetness. A result of preference test using hedonic scale showed an inverse linear relationship between taste quality and total mineral contents.

• 한국지하수토양환경학회:학술대회논문집
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• 한국지하수토양환경학회 2003년도 추계학술발표회
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• pp.334-337
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• 2003

This study was carried out to investigate the effect of soil properties, such as soil organic matter(SOM) content and water content on die-off and regrowth of indigenous microbes due to in-situ ozonation. Four different soils were collected and the soil samples applied to different ozonation time(0-360 min) were incubated during 4 weeks. Population of the indigenous microbes was monitored during incubation period. The number of indigenous microbes in all samples dramatically decreased (more than 90%) within 30 minutes of ozone injection. With increased ozonation time by 360 minutes, the number of the indigenous microbes decreased by 99.99% in all samples. Die-off of the indigenous microbes due to ozone treatment was inversely proportional to SOM and water content. Especially, sample 3 and Sample 4 containing relatively high SOM content and water content showed high regrowth rate, and this resulted from the increase of water soluble and biodegradable organic fraction in soil water after ozone treatment. Soil sample ozonated for 360 minutes showed minor increase in microbial population during 4 weeks of incubation period.

• 생명과학회지
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• 제10권4호
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• pp.368-373
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• 2000

Enteroviruses in the environment pose a public health risk because they can be transmitted via the fecal-oral route through contaminated water, and low numbers are able to initiate an infection in humans. Because the levels of viruses typically found in environmental water and drinking water are low, they must be concentrated from hundreds to thousands of liters of water. Therefore, the main goal of this study was the development of a rapid, simple and efficient procedure to concentrate, isolate and detect enteroviruses from environmental water samples. Viruses were first concentrated by adsorption to 1 MDS cartridge filter and then eluted with approximately 0.5 liter of 1.5% beef extract/0.05M glycin(pH 9.4). In this study, several procedures to concentrate and purify intact viruses from beef extract obtained from the adsorbent filters were tested. Among them, organic floccuration was the best reliable method for reconcentration. sample volume could be reduced to 200∼400 folds and the efficiency of virus recovery through the procedure was over 72%. Finally, the samples were filtered through a membrane disk filter and then analyzed by either the plaque assay or combined cell culture-polymerase chain reaction.

• 한국물환경학회지
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• 제23권1호
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• pp.12-18
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• 2007

Difference of total coliforms (TC) survival time of mixed samples (effluent were mixed by seawater or freshwater) were examined in various conditions. The time taken to achieve a 90% reduction in the TC concentration ($T_{90}$) of effluent, high initial TC concentration and low initial TC concentration samples indicated 143.9, 121.9 and 89.6 hours at $25^{\circ}C$, respectively. At $4^{\circ}C$, log removal rate after 336 hours were 0.96, 1.04, and 1.30. TC survival time of effluent-inoculated seawater sample was longer than that of effluent-inoculated freshwater sample in laboratory. At outdoor condition, TC inactivation curves of effluent-inoculated seawater or freshwater samples showed similar patterns. And both of them were greatly influenced by climate condition. There was not enough evidence that TC survived longer in freshwater than sea water. It was unlikely that the salinity of sea water contributed to the inactivation process of TC.

• 자원환경지질
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• 제31권3호
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• pp.265-271
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• 1998

In the hydrologic and hydrochemical studies of natural waters, oxygen and hydrogen isotope compositions of waters are very important to elucidate the origin and circulation pattern of water in the hydrologic system. The hydrogen isotope analysis of waters usually has been undertaken through the reduction of water to form hydrogen gas using pure metals (in general, zinc and uranium). In 1996, a new apparatus (H/Device) was developed to prepare the water samples (by the reduction with Cr metal) without some intrinsic problems that may yield incorrect and/or inaccurate data, and was installed at 1997 in the Center for Mineral Resources Research (CMR) in Korea University. However, the optimistic conditions of preparation and analysis of samples has not been established. In this paper, we introduce the efficiency of H/Device to obtain accurate hydrogen isotope values of water, and discuss both the optimum conditions including the effective reduction time and the probable mixing (memory) effect between successive samples. We obtained large amounts of a laboratory working standard (KUW; Korea University Water) with the average ${\delta}D_{SMOW}$ value of $-42.1{\pm}1.0$‰ $(1{\sigma})$.

• 한국환경농학회지
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• 제23권4호
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• pp.251-257
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• 2004

Analytical methods were developed to determine cyclosulfamuron residues in soil, water, rice grain and straw using high-performance liquid chromatography (HPLC) with ultraviolet absorption detection. In these methods, cyclosulfamuron was extracted with aqueous $Na_2HPO_4$/acetone and acetone/methanol mixture from soil and rice samples respectively. Liquid-liquid partition coupled with ion-associated technique, Florisil column chromatography, and solid-phase extraction (SPE) were used to separate cyclosulfamuron from interfering co-extractives prior to HPLC analysis. For water sample, the residue was enriched in $C_{18}$-SPE cartridge, cleaned up in situ, and directly subjected to HPLC. Reverse-phase HPLC under ion-suppression was successfully applied to determine cyclo-sulfamuron in sample extracts with the detection at its ${\lambda}_{max}$ (254 nm). Recoveries from fortified samples averaged $87.8{\pm}7.1%$ (n=12), $97.3{\pm}7.2%$ (n=12), $90.8{\pm}6.6%$ (n=6), and $78.5{\pm}6.7%$ (n=6) for soil, water, rice grain and straw, respectively. Detection limits of the methods were 0.004 mg/kg, 0.001 mg/L, 0.01 mg/kg and 0.02 mg/kg for soil, water, rice grain and straw samples, respectively.

• Nuclear Engineering and Technology
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• 제53권1호
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• pp.253-257
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• 2021

This work demonstrates the use of baromembrane method based on reverse osmosis (RO) process. The method is realized on mobile complex, which allows to concentrate and determine ultra-low activity of radionuclides in water cooling ponds of Russian nuclear fuel cycle enterprises. The existence level of radionuclide background creates difficult conditions for identification the contribution of liquid discharges enterprise, as standard monitoring methods have a very high detection level for radionuclides. Traditional methods for determining the background radionuclides concentrations require the selection of at least 500 liters (l) of water, followed by their evaporation to form a dry residue. This procedure with RO membranes requires at least 5 days. It is possible to reduce the time and energy spent on evaporation of hundreds of water liters by pre-concentrating radionuclides in a smaller sample volume with baromembrane method. This approach allows preliminary concentration of water samples from 500 l volume till 20 l volume during several hours. This approach is universal for the concentration of dissolved salts of any heavy metals, other organic compounds and allows the preparation of water countable samples in much shorter time compared to the traditional evaporation method.