• Journal of Nutrition and Health
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• 제17권2호
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• pp.145-153
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• 1984

This study was performed to investigate the effect of various levels of Zn(0, 30, 3000 ppms) and different kinds of lipid(corn oil, sesame oil or butter.) in the diet upon lipid metabolism and Zn & Cu concentration in various organs and tissues in weanling rats. The results obtained were summarized as following : 1) Food consumptions, body weight gains and F.E.R.s showed no significant differences among groups. 2) The contents of total lipids and total cholesterols in serum tended to increase with increase in lipid saturation and Zn levels. Those in per g liver were higher in butter groups and tended to be higher in low Zn groups. Total lipids contents in per g muscle tended to be higher in butter and high Zn groups, but total cholesterols contents in per g muscle tended to be higher in corn oil and low Zn groups. 3) Liver, serum and fecal Zn concentrations tended to be higher in high Zn groups than other Zn groups. The Cu concentrations in liver and serum tended to be lower in high Zn groups. On the contrary, the Cu concentrations in urine tended to be higher in high Zn groups.

• 한국농공학회논문집
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• 제49권2호
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• pp.99-108
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• 2007

The purpose of this study was to investigate characteristics of concentrations of pollutants such as TN (Total Nitrogen), TP (Total Phosphorus) and COD (Chemical Oxygen Demand) in outflow from a nonpoint source dominated watershed ($6.7km^2$). Regular flow measurement and water sampling were taken at five-day intervals during two years (February 2002 to January 2004) in the Ingyeong River, a tributary of the Han River. The mean concentrations of pollutants during rainy days were significantly (p<0.05) higher than those during dry days. For dry days, the flow-weighted mean concentration (0.06 mg/L) of TP during paddy irrigation periods were higher than that (0.02 mg/L) during non-irrigation periods. The seasonal mean concentration of TN was highest in spring likely due to nitrogen fertilization, but those of TP and COD were highest in summer due to particulate phosphorus and sediment-associated organic matter caused by increased discharge. The pollutant concentrations significantly increased with discharge, suggesting that the measures to reduce the increase in the concentrations during storms are needed to control nonpoint source pollution.

• 한국대기환경학회지
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• 제7권1호
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• pp.17-22
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• 1991

Total suspended particulates (TSP) in the atmosphere was collected and size-fractionated by Andersen high volume air sampler for one year (Mar. 1987 $\sim$ Feb. 1988) in Seoul. The concentrations of several polycyclic aromatic hydrocarbons and heavy metals were determined to investigate the atmospheric concentrations, seasonal variations and its relationship with the size distribution of suspended particulate matter. The arithmetic mean concentration of total suspended particulates was 200.44 $\mug/m^3$. The concentrations of heavy metals were 2433.80 for Fe, 629.49 for Zn, 600.71 for Pb, 143.87 for Cu, and 107.21 $ng/m^3$ for Mn, respectively. The concentrations of PAHs were 3.83 for benzo(a) pyrene, 2.95 for benzo(k)fluoranthene, and 4.42 $ng/m^3$ for benzo(ghi)perylene, respectively. PAHs, Pb and Zn abounded in particles below 2.0 $\mu$m, while Fe and Mn aboounded in particles above 2.0 $\mu$m. TSP and its chemical compositions showed the seasonal variations. The concentrations of anthrophogenic pollutants like TSP, PAHs and heavy metals in the fine particles were highest in winter and lowest in summer. PAHs and Pb analyzed showed significant correlations between each other and between TSP concentration in fine particles, indicating that the particles in which they are contained have a similar behavior in the atmosphere.

• Asian-Australasian Journal of Animal Sciences
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• 제30권3호
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• pp.347-354
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• 2017

Objective: The effects of the pre- and postpartum supplementation of cows with Se on their plasma P4 concentrations after calving were investigated. Methods: Thirty-four Holstein cows were used to investigate the effects of dietary selenium supplementation on the postpartum recovery of the luteal function in cows. Selenium-rich yeast (containing 300 ppm selenium) was mixed with total mixed ration fed to 17 pregnant cows from 30 days before they were due to calve (10 g yeast daily) to 100 days after calving (20 g yeast daily). The control cows (n = 17) were fed the same amount of ordinary yeast. The cows' plasma progesterone concentrations were determined every two days using an enzyme immunoassay after calving. Results: Feed intake (total digestive nutrient, crude protein), milk production, body weight and the biochemical properties of blood plasma did not differ between the two groups; however, the plasma selenium concentrations of the supplemented animals were significantly greater than those of the controls at and after calving. The postpartum plasma progesterone concentrations of the selenium-yeast-supplemented group increased earlier than those of the control group. Moreover, during the estrus cycle after the 3rd ovulation or ovulation with estrus between 60 to 80 days after calving, the selenium-supplemented cows exhibited greater progesterone concentrations than the control cows. Conclusion: Selenium supplementation promotes the postpartum progesterone production of cows.

• 한국산업보건학회지
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• 제25권2호
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• pp.166-173
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• 2015

Objectives: The purpose of this study was to evaluate cobalt concentrations in airborne inhalable, total and respirable dust from manufacturing industries using cobalt. Methods: To compare cobalt concentrations, three types of dust samplers(a 37mm closed cassette sampler, Institute of Occupational Medicine(IOM) sampler, and Aluminum cyclone sampler) were used. The analysis of cobalt concentrations was conducted using AAs based on the NIOSH 7300 method. Results: The geometric mean of cobalt concentration in total dust was $1.47{\mu}g/m^3$, and the rate of excess of the Korean Occupational Exposure Limit(KOEL) was 10.0%. The geometric mean concentrations of cobalt in super alloy manufacturing industries were higher than those in plating industries, and molding operations showed higher exposure levels to cobalt than did other operations. Conclusions: The rate of cobalt concentration in inhalable dust from super alloy manufacturing industries exceeding the Workplace Exposure Limit(WEL) as recommended by the Health & Safety Executive(HSE) was 7.1%, which means proper work environmental management is required through wet work environments. Given that molding operations had higher cobalt concentrations, it is necessary to apply measures such as local exhaust for reducing airborne dust in cobalt manufacture industries.

• Environmental Engineering Research
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• 제17권2호
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• pp.95-102
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• 2012

To evaluate the effect of the 4 major rivers restoration project in the Nakdong River to water quality of the river, the Environmental Fluid Dynamics Code (EFDC) and Water Quality Analysis Simulation Program (WASP), are applied in series. Results showed overall decrease in biochemical oxygen demand ($BOD_5$) concentrations and increase in chlorophyll-a concentrations, while total nitrogen and total phosphorous concentrations did not show significant changes, relatively. Decrease in $BOD_5$ concentrations seems to be influenced by an increased hydraulic residence time, which may allow more time for the degradation of organic material. Changes in Chlorophyll-a (Chl-a) concentration, due to the project were more significant for the upper stream areas that show relatively low Chl-a concentration ranges (less than 20 g/L). After the introduction of the Geumho River in the middle part of the Nakdong River, rapid growth of phytoplankton was observed. However, in this middle part of the Nakdong River, the ratio of Chl-a concentration change are less significant, compared to the upper stream areas, due to the project. In the lower stream area, Chl-a concentration decreased after the project. This seems to be resulted from the decreased light availability, due to increased depth, while the nutrient concentrations have been high enough to support phytoplankton growth.

• Journal of Nutrition and Health
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• 제37권4호
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• pp.273-280
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• 2004

This study was conducted to examine the effect of dietary iron levels on lipid metabolism, antioxidative and antithrombogenic capacities in 16-month-old rats. Thirty-two Sprague-Dawley male 16-month-old rats weighing 618 $\pm$ 6 g were raised for 10 days with medium-iron diet (35 ppm in diet) and blocked into 4 groups according to their body weights. One of groups was sacrificed to obtain initial data and the rest 3 groups were raised for 3 months with experimental diets containing different levels of iron (5 ppm, 35 ppm, and 350 ppm). Total lipid, triglyceride and total chole-sterol concentrations in plasma and liver, HDL-cholesterol concentration in plasma, fecal total lipid triglyceride and total cholesterol excretions, thiobarbituric acid reactive substances (TBARS) level in plasma LDL + VLDL (low density lipoprotein + very low density lipoprotein) fractions, blood-clotting time and eicosanoids levels in plasma were measured. The results are as follows: Plasma total lipid, triglyceride and total cholesterol concentrations, TBARS level in plasma LDL + VLDL fractions were increased and blood-clotting time tended to be shortened during 3 months of experimental period. Low (5 ppm) iron diet improved lipid metabolism via increasing HDL-cholesterol and fecal choles-terol excretion. High (350 ppm) iron diet decreased plasma total lipid, triglyceride and total cholesterol concentrations as compared to medium (35 ppm) iron diet and lowered body weight and epididymal fat pad weight. On the other hand, TBARS level in plasma LDL + VLDL fractions and blood-clotting time were increased with high iron diet. It is plausible that low iron diet improves lipid metabolism, antioxidative and antithrombogenic capacities in 16-month-old rats.

• 한국농공학회지
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• 제45권7호
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• pp.49-56
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• 2003

Nonpoint source pollutant loading from watershed may cause a problem to the water quality of the reservoir and stream. The characteristics of stream flow and water quality were monitored to investigate the runoff loading of the Namdae-cheon watershed from May in 1999 to October in 2003. Stage-discharge rating curve at the stream gauging site was established, and annual stream runoff of the study watershed was estimated as 499.4∼1,330.8mm during four years. The concentrations of total-nitrogen and total-phosphorus of stream water quality ranged from 0.76 to 6.95mg/L and from 0.0010 to 0.2276 mg/L, respectively, where T-N was generally higher than the water quality standard 1.0 mg/L for agricultural water use. The loads by unit generation of pollutant mass with respect to population, livestock, land use in this watershed were calculated. The runoff pollutant loadings by concentrations of total-N and total-P were estimated during study period, where the annual runoff loading of total-P was much less than the load by pollutant mass unit generation. The relations between stream discharge and water quality were analysed, and there was a high correlation for total-N but low for total-P. These results will be used to develop the monitoring techniques and water quality management system of agricultural watershed.

• 한국물환경학회지
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• 제34권1호
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• pp.26-32
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• 2018

In order to analyze the effects of sediment on the occurrence of algal bloom on the Giheung Reservoir, the contamination levels of sediments were evaluated. The concentrations of various organic compounds (ignition loss), as well as the total nitrogen, total phosphorus, and heavy metals (Zn, Cr, Co, Ni, Pb, As, Hg, Cd) were analyzed in the sediments taken at eighteen sites of the reservoir. The concentrations of ignition loss and total nitrogen tended to increase from upstream to downstream, and ranged from 4.38 to 12.93% and 2,153 to 4,723 mg/kg, respectively. Heavy metals were in the order of Zn>Cr>Co>Ni>Pb>As>Hg, and the contamination level of the heavy metals was not high as a whole. The concentrations of the total phosphorus were in the range of 765 ~ 3,238 mg/kg, which exceeded the contamination level of the "Sediment Quality Assessment Guideline of River and Lake Sediment (Rule No. 2015-687 of the National Institute of Environmental Research, Korea)" at two upstream sites, four downstream sites, and all downstream sites. These results indicated that the pollution level of the total phosphorus, which is the main factor related to algal bloom, was found to be serious. Therefore, it is necessary to establish a countermeasure for sediment management in order to control the algal bloom which occurs periodically in the reservoir.

• Journal of Community Nutrition
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• 제7권1호
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• pp.3-7
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• 2005

This study was conducted to evaluate nutritional status of school children by biochemical assessment method. Subjects were 308 school children from 4th to 6th grade living in Bucheon city. Their blood glucose, total protein, albumin, total cholesterol, and triglyceride (TG) concentrations were determined. Mean blood glucose concentration was 77.56 mg/dl and $81.2\%$ of children had normal blood glucose concentration. The average proportion of hypoglycemia was $18.8\%$ among the three grades and prevalence of hypoglycemia in 4th grade school children was highest ($21.8\%$). Mean serum total protein and albumin levels were 7.14g/dl and 4.35g/dl, respectively, and all the subjects except only one were in normal range of total protein and albumin. Mean serum TG and total cholesterol concentrations were 145.82mg/dl and 94.50mg/dl. Serum TG and total cholesterol levels showed same pattern that the concentrations decreased in proportion to grade. Especially, there was significant difference between grades in serum total cholesterol. Furthermore, $11.7\%$ of 4th, $6.8\%$ of 5th, and $2.8\%$ of 6th grade school children have borderline hypertriglycemia or hypertriglycemia, risk factors of obesity or cardiovascular disease later in life. Taken together, there was conflict phenomenon that undernutrition of hypertriglycemia and overnutrition of hypertriglycemia existed together. Therefore, it is needed to develop discriminating and personalized nutritional feeding, counseling, and education program to cover the children of under- or over- nutritional status.