• Fisheries and Aquatic Sciences
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• v.2 no.1
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• pp.52-57
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• 1999

Air-drived rotating biological contactor (RBC) system, which is effective method in filtering performance, was tested for the nitrification capacity in a recirculating system. At ammonia concentrations between 0.029 and 0.528 mg/l, the effect of ammonia loading rate on ammonia removal rate at three different hydraulic loading rates could be defined by the following first­order regression models: Hydraulic loading rate of $14.8 m^3/m^3/day:\;y=39.2\times+3.4 (r^2=0.9137)$, Hydraulic loading rate of $26.5 m^3/m^3/day: y=53.3\times+4.0 (r^2=0.8686)$, Hydraulic loading rate of $37.3 m^3/m^3/day: y=58.4\times+4.2 (r^2=0.7755)$, where, $\times$ is ammonia loading rate (mg/l), y is ammonia removal rate $(g/m^3/day)$, The equations showed the optimal ammonia removal rate at the hydraulic loading rate of $26.5m^3/m^3/day$. Below the ammonia concentration of 2.72 mg/l, first-order regression models between ammonia loading rate and ammonia removal rate at three different rates of speed are defined as follows: Rotational speed of $0.75 rpm: y=28.5\times+4.7 (r^2=0.9143)$, Rotational speed of $1.0 rpm: y=33.6\times+8.4 (r^2=0.9534)$, Rotational speed of $2.0 rpm: y=28.9\times+3.6 (r^2=0.9488)$, where, x is ammonia loading rate (mg/l), y is ammonia removal rate $(g/m^3day)$. The equations show the ammonia removal rate at the rotational speed of 1.0 rpm is significantly higher than that at the rotational speed of either 0.75 rpm or 2.0 rpm (P<0.05).

• Korean Journal of Soil Science and Fertilizer
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• v.17 no.1
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• pp.7-11
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• 1984

A study was carried out to develop a modified Gardner's method, which enabled us to obtain simultaneously both the unsaturated hydraulic conductivities and the moisture retention curves by the use of a soil moisture pressure-plate extractor. The unsaturated hydraulic conductivity was calculated from soil moisture changes under different tension ranges in the pressure- plate extractor by means of Gardner's pressure-plate outflow equation. From 30mbar-tension to 10bar-tension, the unsaturated hydraulic conductivities obtained on three soils (Bonryang sandy loam, Yesan silt loam, and Pogog clay loam) varied $3.09{\times}10^{-2}cm/day{\sim}4.06{\times}10^{-6}cm/day$, $1.34{\times}10^{-2}cm/day{\sim}7.30{\times}10^{-6}cm/day$, and $1.83{\times}10^{-2}cm/day{\sim}8.50{\times}10^{-6}cm/day$, respectively. In comparison with the outflow method, it is inconvenient to perform the periodic determinations of the soil moisture content that require release of the applied Pressure before readjusting the pressure desired for each measurement. Nevertheless, the main advantage of the modified method is that the unsaturated hydraulic conductivities of different soils can be calculated simultaneously with a small amount of each soil sample. It is concluded that the unsaturated hydraulic conductivity can be calculated from soil moisture changes in the soil moisture pressure-plate extractor.

• Journal of the Korean Institute of Landscape Architecture
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• v.20 no.1
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• pp.53-68
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• 1992

This study was carried out to estimate the recreation carrying capacity of lawn areas in parks. Recreation carrying capacity in this study is composed of two parts, ecological carrying capacity and psychological carrying capacity. As the first part, this paper deals with the treading times criteria based on the tolerence of the turf to treading pressure. The plant material used for this study was Zoysia japonica, and the treading experiment was done in the experimental fields in Kyungju and Suwon, Korea. The major results of the first part of the study are summarized as follow: 1. As shown in annual change of the growth of the turf, The growth of turt grass was represented by the number of leaf. 2. The tolerance to treading was not significantly different by the time of treading treatment. And the tolerance varies depending on growth rate of grasses, which showed significant relationship with precipitations. 3. From the result of different numbers of simulated treading treatment, the damage of the turf was increased by the increase of the frequency of treading. And the damage was very serious within short period(about 20 days) in high frequency(over 20 times/day) of treading treatment. But low frequency(1∼3times/day) of treading shows good effects on the growth of the turf. 4. The criteria of treading number per day for each carrying capacity level are estimated as 7 times/day for optimum carrying capacity, 13 times/day for standard carrying capacity, and 20 times/day for critical carrying capacity.

• Korean Journal of Community Nutrition
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• v.11 no.1
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• pp.143-151
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• 2006

Regular exercise training improves body composition, blood lipid profiles and exercise adaptation. This study was conducted to investigate the effect of exercise training at different times of day on body composition, blood lipids, stress hormones and nutrient intakes. Twenty four male graduate students carried out this experiment. The subjects were divided into three groups; morning exercise group, evening exercise group and control group. Two exercise groups performed running and muscular resistance training at mid intensity for 12 week periods. Body composition, blood lipid profiles, blood cortisol, ACTH and nutrient intakes were analyzed prior to, midway and after training. There were significant differences about interaction between different exercise times and training periods in plasma TG and HDL-C of the evening exercise training (p < 0.05). Also the evening exercise group was showed the decreasing of TC after training (p < 0.05). No significant differences about interaction between different exercise times and training periods were shown in body composition, stress hormones and nutrient intakes in the three groups. But evening exercise training decreased body fat ($\%$) and blood ACTH (p < 0.05). Also the increasing of carbohydrate intakes was shown by the evening exercise training (p < 0.05). In contrast, morning exercise group indicated a decrease of body fat ($\%$) after 6 week training (p < 0.05), but this effect was not maintained after 12 weeks of training. These results suggested that regular evening exercise is more effect than morning exercise from the viewpoint of improving body composition, blood lipids, nutrient intakes and exercise adaptation.

• Journal of Nutrition and Health
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• v.29 no.9
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• pp.1021-1027
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• 1996

This study examined the patterns of nutrient intakes measured by 1-, 3-, 7-day recalls and records as well as food frequency questionnaire among 59 females volunteers enrolled in the university in Seoul, Korea. Over a 4 month period, a modified Willett food frequency questionnaire was administered once, and a 24-hour dietary recall was conducted 12 times and a weighted dietary record 14 times. From these 12 recalls and 14 records, 1-, 3-, 7-day data were randomly selected. For energy and 11 nutrients, group mean intakes derived from food frequency questionnaire were higher than from recalls and records. Group mean intakes from recalls and records showed little differences depending on days of dietary studies and dietary methods. Measures of agreement were calculated by weighted kappa and intraclass correlation coefficient values calculated for quintile categories while comparing to the results of 26 days recalls and records. Weighted kappa values ranged from 0.11 for riboflavin to 0.36 for vitamin C for and 1-day recall, and from 0.21 for iron to 0.31 for energy for the 1-day record. Weighted kappa values were increased as the number of days of dietary studies increased (0.34-0.57 for the 3-day recalls, 0.27-0.50 for the 3-day records, 0.50-0.68 for the 7-day recalls, and 0.50-0.65 for the 7-day records). Weighted kappa values for food frequency questionnaire were higher than the 1-day data, but lower than the 3-and-7day data(0.34 for energy, 0.31 for iron and 0.22 for vitamin C). Intraclass correlation coefficients ranged from 0.21 for vitamin A to 0.57 for calcium. The degrees of agreement by different methods and days of dietary study are lower in our study compared to agreement by different methods and days of dietary study are lower in our study compared to those in previously published studies for Western populations, partly due to the differences of data analysis methods as well as of dietary patterns between those samples and ours.

• Journal of Environmental Science International
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• v.21 no.6
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• pp.757-761
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• 2012

The purpose of this study was to determine optimum conditions for the cultivation of Tetraselmis suecica (T. suecica) under illumination of four different types of LEDs (i.e., blue, red, white, and mixed). Initial cell concentration was $4{\times}10^4$ cells/mL and temperature of reactor was maintained between 21-$24^{\circ}C$. Specific growth rates were 0.72 $day^{-1}$(white), 0.58 $day^{-1}$(red), 0.49 $day^{-1}$(mixed), and 0.49 $day^{-1}$(blue). Thus, white LEDs was used for the cultivation of T. suecica. Tests with white LEDs under different light intensity, which was conducted to determine optimum light intensity of white LEDs, showed that 9,000 lux of illumination resulted in fastest cell growth and greatest cell concentrations. To avoid shadow effects by dense cell populations, aeration was performed. Cell concentration increased 3.8 times when aeration was used.

• Proceedings of the Korean Society of Crop Science Conference
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• 2017.06a
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• pp.327-327
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• 2017

The effect of different seedling ages and transplanting times on the growth and yield of Indica ${\times}$ Japonica rice for noodle processing was evaluated to develop a high yielding cultivation technology for increasing the competition against the imported foreign rice. Four seedling ages (10-, 20-, 30- and 33-day old) of two Indica ${\times}$ Japonica rice cultivars (cvs. Saemimyeon and Palbangmi) and three transplanting dates (May 20, May 30 and June 9) were used in the study. Our results showed that the growth and rice yield of the two cultivars were significantly affected by the different seedling ages and transplanting times. Dry matter production at the panicle heading of the two rice cultivars were generally higher in the 30-day old seedling than the other seedling age treatments and then gradually decreased as the transplanting time was delayed from May 20 to June 9. Similar high panicle number per square meter were recorded at the 30-day old seedling between May 20-May 30 transplanting times. In contrast, other yield parameters that includes spikelet number per panicle, 1,000-brown rice weight, and ripened grain ratio (except for the June 9 transplanting time of Palbangmi) were not significantly affected. The milled rice yield of Saemimyeon was higher than that of the Palbangmi regardless of seedling ages and it was also the highest at the 30-day old seedling with four seedling ages. The milled rice yield of Saemimyeon was only slightly decreased as the transplanting time was delayed from the May 20 to June 9 but Palbangmi had a significantly lower milled rice yield at June 9 transplanting due to the low ripened grain ratio. The result indicates that the most suitable seedling age for the cultivars tested was at 30-day old seedling for noodle processing rice and recommended transplanting times were between May 20 and May 30 for the high rice yield in the Yeongnam plain area.

• Journal of Environmental Science International
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• v.22 no.1
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• pp.25-35
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• 2013

The concentration of organic compounds was analyzed at each step of BAC process though $BDOC_{total/rapid/slow}$. Further, bacteria communities and biomass concentrations measured FISH and ATP methods were analyzed. The bed volume (BV) of steady state is different from that of based on assessment of organic compounds removal. Bed volumes in DOC, $BDOC_{rapid}$ and $BDOC_{total/slow}$ removal at steady state were around 27,500 (185.8 day), 15,000 (101.4 day) and 32,000 (216.2 day), respectively. A biomass didn't change after the bed volume reached 22,500 (152.0 day) according to analyzing ATP concentration of bacteria. The concentration of ATP was 2.14 ${\mu}g/g$ in BV 22,500 (152.0 day). The total bacterial number was $4.01{\pm}0.4{\times}10^7$ cells/g at the bed volume 1,150 (7.8 day) (the initial operation) and the number of bacteria was $9.27{\pm}0.2{\times}10^9$ at the bed volume 58,560 395.7 day) that increased more than 200 times. Bacterial uptrend was reduced and bacterial communities were stabilized since BV 18,720 (126.5 day). When BV were 1,150 (7.8 day), 8,916 (60.2 day), 18,720 (126.5 day), 31,005 (209.5 day), 49,632 (335.3 day), 58,560 (395.7 day), a proportion of total bacteria for the Eubacteria were 60.1%, 66.0%, 78.4%, 82.0%, 81.3% respectively. ${\gamma}$-Proteobacteria group was the most population throughout the entire range. The correlation coefficient ($r^2$) between Eubacteria biomass and ATP concentration was 0.9448.

• The korean journal of orthodontics
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• v.42 no.5
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• pp.263-269
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• 2012

Objective: To evaluate the antimicrobial effect of different frequencies of brushing with fluoride toothpaste on the levels of salivary mutans streptococci and lactobacilli in children undergoing fixed orthodontic treatment. Methods: The study included 22 patients scheduled for fixed orthodontic therapy distributed between 2 groups with different hygiene regimes. All the subjects received identical braces, bands, and brackets bonded with the same material. Stimulated saliva samples were obtained before placement of the appliance and at 6, 12, and 18 weeks during the therapy. Saliva samples were cultured on selective microbial agar for the detection of microorganisms. Results: Salivary mutans streptococci were significantly suppressed throughout the experimental period in the group that brushed 4 times a day as compared to the group that brushed twice a day. Salivary lactobacilli were not significantly affected by the frequency of brushing with 0.32% sodium fluoride (NaF) toothpaste. Conclusions: The use of 0.32% NaF-containing toothpaste more than 3 times a day has effective antimicrobial activity on mutans streptococci but not lactobacilli in the saliva of children with fixed orthodontic appliances.

• Journal of Bio-Environment Control
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• v.24 no.2
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• pp.119-122
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• 2015

The experiment was carried out to examine the effect of pinching time on growth and marketable yield of okra in rain shielding vinyl houses. Okra (Abelmoschus esculentus L., 'Green sod') seedling was transplanted in May, 2013. Pinching times of okra were in each 30th, 45th, 60th day after transplanting of okra. Shoot branch and top fresh weight were significantly different between each pinching times. Top fresh weight were highest at 60th day pinching time after transplanting investigated, and were lowest at 30th day pinching time after transplanting. There was no significant difference in plant height and stem length among pinching times. According to pinching times, marketable yield and number of okra fruits were varied. Marketable yields were highest at 60th day after transplanting, whereas were lowest at 30th day after transplanting. Mineral concentrations of okra fruits were not significantly different among pinching times. Therefore pinching times 60th day after transplanting was effective to increase yield of okra fruit in rain shielding vinyl houses.