• 한국임상수의학회지
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• 제17권1호
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• pp.76-82
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• 2000

This study was undertaken to find out the effect of persimmon leaves on histopathological changes of cadmium toxicity in mice. Seventy two BALB/c mice of male were divided into a control group(A) and five experimental groups (B, C, D, E, F) : group A received tap water and basal diet, group B received tap water and diet supplemented with 3% persimmon leaves alone, group C received basal diet and 300 ppm cadmium, group D, E and F received basal diet supplemented with 1, 3% and 7% persimmon leaves and 300 ppm cadmium respectively. Cadmium dissolved in tap water was used, and the persimmon leaves were mixed with feed. All mice were dissected on the 84th day. Pathological changes in liver, kidney, cortical osseous tissue of femoral shaft, bone trabecular of femur, and epiphyseal cartilage plate of femur were observed. Group B showed no significant changes as the control group. But group C showed the unclearness of specific cells in liver, the loss of architecture and necrosis of hepatocyte, degeneration and necrosis of renal convoluted tubules, desquamation and vacuolization of the greater part of the renal tubular epithelium, marked thinning of the cortical osseous tissue in femoral shaft, reduction of cancellous bone volume and decreaswe of trabecular number, and marked thinning of epiphyseal cartilage plate in femur. On the other hand, persimmon leaves-treated group showed a little convalescent changes an maintained their normal architectures in liver, kidney, cortical osseous tissue of femoral shaft, bone trabecular of femur, and epiphyseal cartilage plate of femur.

• Environmental Analysis Health and Toxicology
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• 제24권4호
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• pp.293-301
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• 2009

This study was conducted to investigate the distribution of the concentrations of selected trace metals and inorganic anions in five types of drinking water samples (mineral spring water, well water, small community water, municipal tap water, and commercial mineral water) collected from Chuncheon, Gangwon-do in 2007. Forty four samples were analyzed for five metals and five anions using an atomic absorption spectrometer and an ion chromatograph, respectively. Arsenic (As) and nitrate (${NO_3}^-$) concentrations in some groundwater samples did not meet the future (10 ${\mu}g/L$) and current (44 mg/L) Korean drinking water standards, respectively. On the other hand, any municipal tap water samples, the sources of which were lake surface water, satisfied the Korean standards. Human health risk assessment results showed that arsenic in all types of water, especially groundwater including commercial mineral water, may pose both noncarcinogenic and carcinogenic effects on the residents. It is concluded that groundwater is not safe drinking water any longer and that a national survey and follow-up measures need to be taken.

• 생물환경조절학회지
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• 제16권4호
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• pp.322-327
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• 2007

본 연구는 서낙동강 유역 평강천의 수질을 분석하고 이 하천수의 대체 용수원으로 지하수나 빗물이 가능한지를 검토코자 수행되었다. 평강천의 염 농도(EC)는 계절에 따라 차이가 컸으며 갈수기인 3월${\sim}$5월에는 EC $3.22{\sim}3.62dS{\cdot}m^{-1}$로 매우 높았고 성수기인 6월부터 점점 낮아져 9월에는 EC $2.37dS{\cdot}m^{-1}$까지 낮아졌다. 염 농도(EC)늘 평강천의 위치에 따라 많은 차이를 보여 상류는 EC $0.71dS{\cdot}m^{-1}$, 중류는 $2.38dS{\cdot}m^{-1}$, 하류는 $3.02dS{\cdot}m^{-1}$였다. 초장, 생체중, 건물중 등 생육이 토마토, 오이 모두 하천수보다 빗물이나 수돗물에 좋았다. 평균과중은 토마토는 수돗물이 가장 무거웠으나 오이는 처리간에 유의차는 없었다. 착과수는 토마토, 오이 모두 하천수가 가장 적었으며 빗물과 수돗물간에는 차이가 없었다. 수량은 토마토에서는 수돗물이 10,594kg/10a으로 가장 많았으며 빗물, 하천수 순이었다. 오이는 각각 수돗물이 11,826, 빗물이 10855kg/10a로 하천수보다 44,33%많았다. 토마토 과실의 품질에서 당도는 하천수가 다소 높은 경향이었으나 처리간에 차이가 없었으며 배꼽썩음과의 발생은 하천수가 가장 많았다. T-N 및 P의 함량은 토마토, 오이 모두 처리간에 차이가 없었으며 Ca 함량은 토마토에서는 하천수보다 빗물이나 수돗물이 많았고 오이에서도 같은 경향이었다. 반면 Na 함량은 Ca와 달리 하천수에서 가장 많았다. 이상의 결과에서 서낙동강 유역의 농업 용수원으로 하천수 대신 지하수나 빗물을 이용하면 토마토 생육에 효과적일 것이라 생각된다

• 대한소아치과학회지
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• 제34권1호
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• pp.36-42
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• 2007

외상성 손상 후 치아 탈구 시 치아를 저장하는 저장용액의 종류와 온도가 치주인대세포의 생존율에 어떠한 영향을 미치는지 연구하기 위하여 치주인대세포를 10% fetus bovine serum(FBS) 함유 ${\alpha}-minimal$ essential medium$({\alpha}-MEM)$에서 $37^{\circ}C$ 5% $CO_2$ 공기 혼합 배양기에서 배양하고 4 25, $37^{\circ}C$의 Hank's balanced salt solution(HBSS) 과 ${\alpha}-MEM$, 우유(S회사, P회사), tap water에 저장하고 60분이 지난 후 각 군에 대해 치주인대세포의 생존율을 측정하기 위하여 MTT assay를 시행하여 다음과 같은 결과를 얻었다. 1. $4^{\circ}C$ 저장용액의 치주인대세포의 생존율은 ${\alpha}-MEM$과 P회사우유에서 가장 높았고 HBSS, S회사우유, tap water 순으로 낮았다. 2. $25^{\circ}C$ 저장용액의 치주인대세포의 생존율은 ${\alpha}-MEM$에서 가장 높았고 P회사우유, HBSS, S회사우유, tap water 순으로 낮았다. 3. $37^{\circ}C$ 저장용액의 치주인대세포의 생존율은 ${\alpha}-MEM$과 P회사우유, HBSS, S회사우유에서 높았고 tap water에서 가장 낮았다. 4. ${\alpha}-MEM$의 치주인대세포의 생존율은 $4^{\circ}C$에서 가장 높았고 $25^{\circ}C$와 $37^{\circ}C$순으로 낮았으며 HBSS에서는 $4^{\circ}C$에서 높았고 $25^{\circ}C$와 $37^{\circ}C$에서 낮았다. 5. S회사와 P회사우유에서 치주인대세포의 생존율은 $4^{\circ}C$와 $25^{\circ}C$에서 높았고 $37^{\circ}C$에서 낮았다. 이상의 결과를 종합해볼 때 외상으로 인해 치아가 탈구되었을 때 탈구된 치아의 저장용액으로 HBSS용액이 추천되고 있으나 이 연구에서 $4^{\circ}C$와 $25^{\circ}C$ 우유에서 치주인대세포의 생존율이 높았으므로 사고 현장에서 쉽게 구할 수 있고 치주인대세포의 생활력 보존에도 유리한 낮은 온도의 우유에 탈구된 치아를 보존하는 방법도 좋을 것으로 생각된다.

• Journal of Preventive Medicine and Public Health
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• 제22권4호
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• pp.495-505
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• 1989

This study was conducted as a nationwide survey In Korea to determine the THM (trihalomethane) concentration levels in the drinking water of 14 selected cities. The survey was underdtaken in one city (Kwangju) during September and October of 1988 and 14 cities in January through February of 1989. The results were as follows : 1. The $KMnO_4$ consumption was 10.6mg/l-11.6mg/l in Pusan and Ulsan, exceeding the drinking water standard of 10mg/l. Pusan, Inchon, Kwangju, Ulsan, Mokpo and Junju areas also exceeded the ammonia nitrate standard of 0.5mg/l. Other tap waters surveyed were detected below the drinking water standards. 2. The THM concentrations of tap water measured in January and February of 1989 were detected in the range $1.20{\mu}g/l-150.8{\mu}g/l$. 3. In the comparative study of the THM concentration of tap water measured in the Kwangju area during September and October of 1998, the average THM concentation of $145.63{\pm}70.72{\mu}g/l$ showed a sixfold increase compared to that of $23.8{\pm}8.31{\mu}g/l$ surveyed in January and February 1989. 4. The proportion of the four THM compounds found in tap water was bromoform, 47% ; chloroform, 30% ; chlorodibromomethane, 13% ; and dichlorobromomethane, 10%. 5. Since the results indicate that the concentration of bromoform was 2-10 times higher than that of chloroform measured in the seaside district of Pusan, Ulsan and Cheju Island, it is reasonable to assume that the raw water was somehow Influenced by seawater. 6. The average lifetime cancer rate of the population exposed to chloroform measured in the surveyed areas was 17 cancer incidences per 1 million population. From the above results, the existence of THM in the distribution systems seems to be inevitable, since chlorine disinfection is performed in water treatment plants In our country. There seems to be a trend of increasing. THM cncentrations due to the contamination of raw water. In order to establish my form of regulations, health risk assessment is an imminent subject.

• Asian Journal of Business Environment
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• 제10권4호
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• pp.29-34
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• 2020

Purpose: Town of Woldia, a semi-arid region in the Northern Wollo region of Ethiopia, faces water supply shortage in general, though the town possesses a running stream of clean water throughout the year. This study is aimed at analyzing the possibility of using rainwater for water scarcity and non-potable water needs of the Woldia University. A careful study and analysis have been made to assess the feasibility of using rainwater in place of the tap water supply. Research design and methodology: This study was done inside the main campus of Woldia University located in Woldia town. The runoff water from the roof of buildings was studied, by the time of rainfall in the town. Also, the budget needed for implementing a rainwater harvesting system was calculated. Results: The findings of the study clearly indicates that the requirements of the water to use for flushing, cleaning, and washing toilets in the administrative buildings and classrooms can be satisfied by using rainwater as an alternative to tap water. Conclusion: Based on the results the study finds it is benefitable for the Woldia University to install the rainwater harvesting system at the earliest to solve the water problems prevailing in the current situation.

• 상하수도학회지
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• 제33권4호
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• pp.269-279
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• 2019

This study would present a risk analysis method to evaluate stable tap water supply in a multi-regional water supply system and propose a measure for the evaluation of the effect of the conjunctive operation of the multi-regional water supply system using this. Judging from the vulnerability for the crisis response of the entire N. multi-regional water supply system, as compared to the result of Scenario 1 in which no conjunctive pipes were operated, it was found that in Scenario 2, in which conjunctive pipes were partially operated, the vulnerability of crisis response decreased by about 30.6%, and as compared to Scenario 3, the vulnerability of crisis response decreased by 86.2%. In setting a plan for stable tap water supply in N multi-regional water supply system, using the estimated value and the method for the evaluation of the vulnerability of crisis response by pipe, by interval and by line, it is judged that this can be utilized as a basis for the judgment of the evaluation of the operation or the additional installation of conjunctive pipes.

• Asian-Australasian Journal of Animal Sciences
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• 제12권8호
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• pp.1277-1284
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• 1999

Eight feeds and their residues left after washing with tap water (water residue) or incubation in the rumen (rumen residues) were treated with hydrochloric acid, neutral detergent solution without EDTA (NDS) or both, and the release or sorption of minerals (Ca, Mg, P, Na, K, Cu and Zn) assessed. Six of the feeds were from Sri Lanka (Panicum maximum ecotype Guinea A, Glyricidia maculate, Artocarpus heterophyllus (jak leaves), untreated and urea-treated rice straw, and rice bran) and two from the Netherlands (maize silage and wheat straw). The initial concentration of mineral elements, the concentration of neutral detergent fibre (NDF) and the type of feed significantly influenced (p<0.01). The proportion of the mineral elements released or sorbed. In general, feeds with high NDF content (straws and guinea grass) sorbed Ca from tap water, or released less in the rumen, and within these feeds the extent of sorption varied with source of fibre. Acid or NDS treatment removed little of the sorbed Ca, but they removed much of the Mg from both water and rumen residues. Fibres of wheat straw and jak leaves showed an affinity for Mg in the rumen. All feeds and their water and rumen residues sorbed P and Na from NDS, and the extent of sorption varied with the initial concentrations of these elements and with the type of fibre. Acid treatment removed part of the sorbed Na, but not the P. The solubility of K was not affected by the content of NDF, the type of fibre or the initial concentration of K. All feeds and their residues, except for the rumen residues of rice bran sorbed Cu from tap water and in the rumen. The recovery of Cu in rumen residues declined from 353% to 147% after NDS treatment, and with some feeds (glyricidia and jak leaves) the recovery was below 100%. Acid treatment removed part of the Zn sorbed by the water and rumen residues, but the capacity of residues to retain Zn varied with the type of feed.

• Journal of Preventive Medicine and Public Health
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• 제38권4호
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• pp.457-464
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• 2005

Objectives : An outbreak of salmonellosis occurred among the student s and staff of D primary school in Yeongcheon-si, 2004. This investigation was carried out to prevent any recurrence of this outbreak and to study the infection source and transmission of the salmonellosis. Methods : The authors conducted a questionnaire survey among 1,205 students and staff members from D primary school about the ingestion of the school lunch and drinking water, and the manifestation of their symptoms. The author examined rectal swabs, the tap water and microorganism cultures, and we also investigated the dining facility and water supply facility. Results : The diarrheal cases were defined as the confirmed cases or the persons who had diarrhea more than one time with symptoms such as fever, vomiting and tenesmus. The diarrheal attack rate was 28.0%. Ingestion of fried bean curd with egg had a significantly high association with the diarrheal attack rate (p<0.05), and the relative risk of the fried bean curd with egg was 10.68 (95% CI=3.88-29.41), as was determined by logistic regression analysis. The bacterial counts in the tap water of the food preparation room and toilet (first floor) exceeded the maximum permissible counts. S. Enteritidis bacteria were only cultured from the fried bean curd with egg of all the supplied foods on September 3, 2004. Conclusions : The major cause of salmonellosis was presumed to be the contaminated bean curd via contaminated tap water due to a water leak of a school water pipe. This contaminated bean curd was under prepared, which allowed the S. Enteritidis to survive and multiply prior to its ingestion.

• 한국마린엔지니어링학회:학술대회논문집
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• 한국마린엔지니어링학회 2000년도 춘계학술대회 논문집(Proceeding of the KOSME 2000 Spring Annual Meeting)
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• pp.115-121
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• 2000

As the development of industry water quality of river is going to bad because of waste water of an industrial complex and general home agricultural chemicals exhaust of $SO_3$ and CO gas acid rain and so on. Corrosion damage of boiler factory equipment and so forth occur quickly due to using of the polluted water resulting in increasing leak accident. Especially working life of hot water boiler using the polluted water becomes more short and energy loss increases. The cathodic protection method is the most economical and reliable one to prevent corrosion damage of steel structures. Mg-base alloys galvanic anode protection of cathodic protection method is suitable for than application of hot water boiler using water with high specific resistance such as tap water. This paper is studied on the cathodic protection characteristics of how water boiler. In tap water and 0.001mol/$\ell$ NaCl solution the characteristics of anodic polarization of Mg-base alloys galvanic anode and tube material is investigated the measurement of cathodic protection potential according to the time elaspsed is carried out.