• 동위원소뉴스
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• no.12 s.12
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• pp.8-9
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• 1997

• 수도
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• s.66
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• pp.90-107
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• 1994

일반 정수시설의 설계는 15년 이전경까지는 기성의 기본 Pattern에 따라서 토목기사에 의해서 행해져 왔고 괄목 할만한 변화는 보이지 않았다. 그러나 최근은 살균처리에 따른 부생성물의 발암성에 대한 공포 때문에 미국의 EPA는 음료수의 허용수질의 대폭 개정을 행함과 동시에 살균제, 살균처리의 기준, 발암성이 의심스러운 물질량의 제한, 여과수 탁도의 저감, 급수관의 부식을 방지하기 위한 정수 수질의 조정 등을 공공 수도에 의무화했다. 따라서 이와 같은 조건을 만족시키는 정수처리 계통과 그에 따르는 계장 시설과 정수관리가 필요하며, 화학, 화학 공학, 미생물학, 계장공학 등의 넓은 분야의 전문 지식이 토목 공학에 첨가해서 필요하게 되었다.

• Korean Journal of Food Science and Technology
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• v.37 no.4
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• pp.671-677
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• 2005

Conformity to legal permission standard of $5\;log_{10}$ CFU/mL reduction of foodborne pathogens or spoilage bacteria such as Escherichia coli, Staphylococcus aureus, Salmonella typhimurium, Pseudomonas aruginosa, and Enterococcus hirae was examined in 11 domestic commercial sanitizers and disinfectant. One chlorine compound, two iodophor compounds, two peroxide compounds, and three quaternary ammonium compounds (QACs) met advised standard concentration (100%), showing $7\;log_{10}$ CFU/mL reduction, and met legal standard by $5-6\;log_{10}$ CFU/mL reduction at 75% of advised standard concentration. At 10% dilution, one chlorine compound, one iodophor compound, two peroxide compounds, and two QACs satisfied legal standard.

• Korean Journal of Food Science and Technology
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• v.40 no.2
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• pp.228-233
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• 2008

Ultraviolet sterilizers (UVS) are widely used in restaurants, cafeterias and catering businesses in Korea. The proper application of UVS, however, is still questionable since no studies have clearly identified their efficacy and safety, while regulations and regulatory management systems are yet to be established. In the present study, the efficacy of UVS were investigated by measuring spatial UV intensity inside five commercially operated UVS. The operating safety parameters were also checked by measuring leaked UV intensity. The UV intensities were inversely proportional to distance from the UV lamp within 25 cm, and to the square of the distance exceeding 25 cm. The UV intensities in commercial UVS varied with the distance from UV lamp and the incident angle, highlighting efficacy and stability concerns. Notable leakage was detected through the door gaps of a studied UVS, which also brought about safety concerns. Allowable working distances for the UV leaking UVS were suggested based on international standards.

• Journal of Food Hygiene and Safety
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• v.33 no.1
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• pp.83-88
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• 2018

The purpose of this study was to investigate and evaluate the safety of the wet tissues. In this study, we analyzed sterilizing preservatives and the presence of harmful substances in 62 wet tissue samples in the market. The contents of preservatives, formaldehyde and methanol were analyzed by HPLC and headspace-GC, respectively. Cetylpyridinium chloride was detected as 7-13 ppm in 5 samples. Sodium benzoate was detected in 46 samples ranging from 200 ppm to 3500 ppm, and 9 ppm of methylparahydroxy benzoate was detected in 1 sample. Propylparahydroxy benzoate was not detected in any samples. 5 ppm of methylchloroisothiazolinone and 140 ppm of methylisothiazolinone were detected in 1 sample. Formaldehyde was detected as $0.0069-1.796{\mu}g/g$ in 59 samples. Methanol was detected ranging from 2 ppm to 51 ppm in 22 samples, and 4 samples showed more than 20 ppm of the legal limit. The pH of the wet tissues was 4.0 to 8.2. Continuous investigation and monitoring are necessary to ensure safe distribution of products.

• The Korean Journal of Pesticide Science
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• v.16 no.4
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• pp.288-293
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• 2012

The dissipation patterns of amisulbrom in cucumber under a greenhouse condition was investigated to establish biological half-life and pre-harvest residue limit (PHRL). Amisulbrom residue in/on cucumber on the day of application under standard application condition was $0.15mg\;kg^{-1}$ and decreased to $0.06mg\;kg^{-1}$ after 5 days after treatment, so that biological half-life calculated 3.6 day, while initial concentration of amisulbrom twice application 3 days interval under standard application condition was $0.35mg\;kg^{-1}$ and decreased to $0.09mg\;kg^{-1}$ after same period and the biological half-life calculated 2.4 day. PHRL was suggested by prediction curve calculated from the decay constant of amisulbrom at standard rate. For example, $1.83mg\;kg^{-1}$ at 5 days before harvest and $1.03mg\;kg^{-1}$ at 2 days before harvest were suggested.

• Journal of Dairy Science and Biotechnology
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• v.36 no.2
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• pp.95-105
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• 2018

Since 2018, the Korean government has permitted the production and sale of any cheese made from raw milk and aged for at least 60 days. The present study aimed to investigate the sensory characteristics of various types of Gouda cheese produced from raw milk during 60-day aging. The average pH of the raw milk used in this experiment was $6.7{\pm}0.4$, similar to that of the sterilized milk. The pH of raw-milk Gouda cheese was $5.2{\pm}0.5$ a day after the 60-day aging period, wherein the pH was $5.5{\pm}0.3$. In total, 5 samples were used for sensory evaluation in this experiment: Cheeses 1~5. With respect to flavor, Cheeses 1 and 5 received the highest and lowest scores, respectively. Raw-milk Gouda cheese produced using Salmonella spp.-contaminated raw milk was not greatly influenced by flavor; however, it had a negative effect on its appearance. In the future, it is imperative to carry out sensory evaluation of cheese produced with raw milk contaminated with various food-contaminating bacteria.

• Korean Journal of Environmental Agriculture
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• v.31 no.1
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• pp.45-51
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• 2012

BACKGROUND: This study was carried out to establish pre-harvest residue limit of fungicides pyrimethanil and trifloxystrobin in persimmon, based on dissipation and biological half-lives of two fungicides residue. METHODS AND RESULTS: Both pyrimethanil and trifloxystrobin were extracted with acetonitrile, clean-up with $NH_2$ SPE cartridge and residue were analyzed by HPLC/DAD. Limit of Detection was 0.01 mg/kg. Average recovery were $81{\pm}1.62%$, $98{\pm}1.58%$ of pyrimethanil, and $91{\pm}2.94%$, $98{\pm}1.25%$ of trifloxystrobin at fortification levels at 0.1 and 0.5 mg/kg, respectively. CONCLUSION: The biological half-lives of pyrimethanil were 15.6 and 11.6 days at sprayed with recommended and double dosage, respectively. The biological half-lives of trifloxystrobin were 10.4 and 10.3 days at sprayed with recommended and double dosage, respectively. The pre-harvest residue limit of pyrimethanil and trifloxystrobin were recommended as 2.69 and 0.83 mg/kg for 10 days before harvest, respectively.

• Current Research on Agriculture and Life Sciences
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• v.31 no.4
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• pp.272-279
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• 2013

The dissipation patters of the triazole fungicides flusilazole and myclobutanil in apples were investigated to establish the biological half-lives and pre-harvest residue limits (PHRLs). The residual amounts of the fungicides sprayed with single or triple doses were below the maximum residue limits (MRL) for apples established by Ministry of Food and Drug Safety. The dissipation constants of the fungicides in the apples were 0.0513 for flusilazole and 0.0244 for myclobutanil meaning their biological half-lives were calculated as 6.2-6.7 days for flusilazole and 13.3-24.8 days for myclobutanil. The PHRLs calculated using the dissipation constants indicated that the residual amounts of flusilazole and myclobutanil in the apples at the harvesting date would be below the MRLs if their residual amounts were 0.43 and 0.59 mg/kg, respectively, at 7 days prior to harvesting the apples.

• Korean Journal of Agricultural Science
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• v.6 no.2
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• pp.158-165
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• 1979

These studies were carried out to investigate the freshness and bacteria of ultra high temperature processed market milks which treated and distributed in four districts: Kwangju, Daejon, Sungwhan and Seoul, and to elucidate their keeping qualities when stored in refrigerator and at room temperature. Various samples taken from the four districts were tested and the results obtained were as follows. 1. Samples from three districts retained acidities fit for standard for 9 days and those from one district for 5 days when stored at $4^{\circ}C$. However, the periods were shortened to 1 day for samples of the three districts and to same day for those of one district when stored at $20^{\circ}C$. 2. Negative results were obtained from alcohol and boiling tests upto 10 days for samples of the three districts and upto 6 to 7 days for those of one district when stored at $4^{\circ}C$. But positive results were recorded after 2 days for samples of the three districts and after 1 day for those of one district when stored at $20^{\circ}C$. 3. Total viable number of organisms did not exceed the standard limit upto 10 days for sample of one district, up to 7 days for those of two districts and upto 2 days for those of the other when stored at $4^{\circ}C$. But in case of storage at $20^{\circ}C$, samples of one district maintained viable titre below the limit for 1 day and samples of three districts for same day. 4. Initial number of psychrophilic were $4.8{\times}10^3/ml$ on an average. This titre was increased to $6.4{\times}10^7/ml$ gradually during 10 days when stored at $4^{\circ}C$, and to $5.2{\times}10^7/ml$ during 2 days. when stored at $20^{\circ}C$. 5. Number of thermoduric bacteria were below $10^2/ml$ for 10 days in samples of three districts and for 6 days in those of the other when stored at $4^{\circ}C$. However, in case of storage at $20^{\circ}C$, the titre exceeded $10^2/ml$ after 1 day in samples of three districts. 6. No coliform bacteria were detected in all samples from the four districts.