• 한국환경과학회지
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• 제8권3호
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• pp.319-323
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• 1999

This study was designed to evaluate the exposure to benzene by residents in neighborhoods near a major roadways, by persons waiting buses, and by drivers and service station attendants while refueling. It was confirmed that the outdoor air benzene concentrations near the major roadways were higher than those further away from the sources. However, neither the indoor air nor breath concentrations were different for two specified residential areas. Smoking was confirmed as an important factor for the indoor air benzene levels. Persons waiting buses, drivers and service station attendants were exposed to elevated benzene levels compared to even the residents in neighborhoods near a major roadways. The mean benzene concentration at bus stop was 2.7 to 6.9 times higher than the mean ambient air concentration. The mean benzene concentrations in the breathing zone of drivers and service station attendants were 95 to 160 and 120 to 202 times higher than the mean ambient air concentrations, respectively.

• 한국식품영양학회지
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• 제6권2호
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• pp.109-114
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• 1993

This study was divised to observe an Inhibitory effect toward a lipolytic action of toxohormone-L from large root and small root Nepal pseudo ginseng (NPG ; Nepal products) components by water extract and ethanol precipitate in vitro. Toxohormone-L is known to be a lipolytic factor that was partially purified from the ascites fluid of Sarcoma 180-bearing mice and of patients with hepatoma. The inhibitory effect that inhibited the lipolytic action of toxohormone-L by ethanol Precipitate component of large root NPG (mean 55.5%) was higher (mean 1.37 times) than that of water extract component in final reaction concentration of 500 and 1, 000ug/ml, on the other side inhibitory effect of water extract component in small root NPG (mean 55.5%) was higer (mean 1.14 times) than that of ethanol precipitate component. In a way inhibitory effect of precipitate component In large root NPG(47.6%), when final reaction concentration of sample were 1, 000ug/ml, was about 40% lower than that of Korean red ginseng.

• 한국식품영양학회지
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• 제4권1호
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• pp.75-80
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• 1991

This study was divised to observe an inhibitory toward a lipolytic action of toxohormone-L from large root and small root Nepal pseudo ginseng(NPG ; Nepal products) components by water extract and ethanol precipitate in vitro. Toxohormone-L Is known to be a lipolytic factor that was partially purified from the ascites fluid of sarcoma 180-hearing mice and of patients with hepatoma. The inhibitory effect that inhibited the lipolytic action of toxohormone-L by ethanol precipitate component of large root NPG(mean 46.8%) was higher (mean 1.8 times) than that of water extract component in final reaction concentration ,5001g1m1, on the other side inhibitory effect of water extract component in small root NPG(mean 43.9%) was higher(mean 1. 2 times) than that of ethano1 precipitate component, respectively. In a way inhibitory effect of ethanol precipitate component in large root NPG(47.6%), when final reaction concentration of sample were 1,000 U g/ml, was about 4095 lower than that of Korean red ginseng, respectively.

• 한국산업보건학회지
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• 제19권1호
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• pp.8-15
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• 2009

This study was examined to find out asbestos exposure level the factors which affected the level at asbestos abatement sites. We visited a total of thirteen building demolition sites(3 apartments, 3 schools, 4 stores, and 3 houses) were visited to collect samples and related data from August to November, 2006. The results of this study were as follows 1. The results of an analysis of bulk samples to identify types of asbestos at the asbestos abatement sites showed that the kinds of the asbestos detected were chrysotile by 50.0%, were tremolite by 2.6%, and were the contents of chrysotile by 3 to 20%. 2. The geometric mean concentration of asbestos was 0.007 f/cc(range 0.001-0.34 f/cc) and its geometric standard deviation was 5.83. Of the samples, however, 12 exceeded the Korean Occupational Exposure Limit(0.1f/cc). 3. Of the materials, textile material had the highest concentration with geometric mean of 0.016 f/cc. When asbestos-containing materials were removed using T type tools, the geometric mean concentration of asbestos was 0.061 f/cc. The level by this method was much higher than by other removal methods. In analysis by the type of building, the geometric mean concentration of asbestos in stores was 0.042 f/cc and was higher than in other buildings. 4. The Poisson regression analysis was applied to find out the factors that affect the airborne asbestos concentration. As a result of the analysis, removal using a T type tool was the most important factor affecting the asbestos concentration(p<0.01). In conclusion, the airborne asbestos concentration(geometric mean) in asbestos abatement sites was 0.007 f/cc(0.001~0.34 f/cc), and 12(14.6%) of all samples were over the 0.1 f/cc. These results showed that asbestos abatement workers have been exposed to the high level of airborne asbestos because they have not been keeping asbestos removal rule. In accordance with increases of the number of building demolition sites, the better government regulation on asbestos abatement methods should be made and be performed well at building demolition sites.

• 한국지열·수열에너지학회논문집
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• 제15권4호
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• pp.24-31
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• 2019

In this paper, we simulated a new apartment building by using radon emission test values from various building materials used as interior finishing materials. The simulations evaluated the radon concentration in the room according to the radon emissions and the ventilations for each type of finishing material (gypsum board, stone, tile and concrete). Overall concrete finish simulation case showed the highest concentration than the case using other materials due to the effect of wall area at the center of each room and the mean radon concentration at 1.5 m above the floor was slightly lower than the mean value at each center. In the case of the porch, pantry and bathroom, the radon concentration was high even when the same materials were used as in the other rooms.

• 한국물환경학회지
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• 제22권3호
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• pp.504-512
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• 2006

In order to estimate microbial contaminant discharge from diffuse sources, rainfall runoff was monitored at forestry, agriculture and urban watersheds. Total coliform and E. coli were monitored at the study watersheds as they are regulated by the environmental laws. Concentration and EMC (Event Mean Concentration) of coliform of rainfall runoff at the urban watershed were the highest followed by those from agricultural and forestry watersheds. By monitoring coliform concentrations of overlying water and sediment at five monitoring points in the downstream of the Geum River, average concentration from spring to summer was higher than those values from fall to spring. Coliform concentrations in the pore water were higher compared to those of overlying water and closely related with flow rate of the river.

• 한국염색가공학회지
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• 제19권5호
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• pp.30-36
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• 2007

Cypermethrin-containing polyurea microcapsules were prepared by interfacial polymerization using aromatic 2,4-toluene diisocyanate(TDI) and Ethylene diamine(EDA) as wall forming materials. The effects of the protective colloids of polyvinylalcohol(PVA) and gelatin were investigated through experimentation. The mean size of the polyurea microcapsules was smaller and the surface morphology of the PVA was much smoother than gelatin. In addition the release behavior was much more controlled and better sustained. As the concentration of protective colloid increased, the wall membrane of the polyurea microcapsules became more stable, the thermal stability of the wall membrane increased, the mean particle size became smaller, and the particle distribution was more uniform. The release behavior of the core material changed according to the concentration. As the gelatin concentration was increased, a more controlled and sustained release behavior was observed. However, in the case of PVA, the increase of PVA concentration lead to a more rapid release rate.

• 대한산업공학회지
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• 제15권2호
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• pp.103-108
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• 1989

PERT formulae for the mean and variance of activity time are near exact only over a short interval of the concentration parameter which is defined as the sum of the two shape parameters of the beta distribution. Aiming a better estimation of the mean and variance of activity time, we propose a method of subjectively estimating this concentration parameter via estimating the probability of completing the activity within a specified time interval.

• 대한용접접합학회:학술대회논문집
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• 대한용접접합학회 2005년도 춘계학술발표대회 개요집
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• pp.115-117
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• 2005

The purpose of this study is to establish the fatigue design criteria for the notched structural components subjected to high mean stress. In order to do it, the effects of stress concentration factor on the monotonic and cyclic tensile properties were investigated. Based on the results, two fatigue design approaches for the notched specimen using Goodman diagram was established and verified by comparing with the experimental result.

• Journal of Nutrition and Health
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• 제36권7호
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• pp.729-735
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• 2003

This study was performed to evaluate the effect of iron supplement for 4 weeks on iron status, immunity, and antioxidant status of national female soccer players (n = 25). This study was performed at summer hard training period right before competition. A single blind design was used to divide the subjects into iron-supplement (IS) or placebo group (P). Iron-supplement group was supplemented with iron (40 mg/d) for 4 weeks. The mean age of the subjects was 23.3 $\pm$ 2.5 years old. Mean height and body weight of the subjects were 164.4 $\pm$ 5.7 em and 57.4 $\pm$ 4.6 kg, respectively. The mean carrier as soccer player was 11.0 $\pm$ 2.6 years and mean training time was 7.0 $\pm$ 1.3 hr/day. The mean hemoglobin, hematocrit, total iron binding capacity and ferritin concentrations before iron supplementation were not different between two groups. After 4 weeks of summer training and iron supplementation, serum ferritin level was significantly increased only in IS group after supplementation. Mean corpuscular volume and total iron binding capacity were significantly decreased in both groups. Meanwhile, hemoglobin and red blood cell count were significantly lowered only in placebo group. The IgM concentration increased significantly in both groups, but IgG concentration had increasing tendency only in IS group (p < 0.064). Therefore, iron supplementation during hard training period may be helpful to improve work capacity of the athletes by improving ferritin status and humoral immune responses.