• Fisheries and Aquatic Sciences
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• 제2권1호
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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).

• 한국토양비료학회지
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• 제17권1호
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• pp.7-11
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• 1984

토양(土壤)의 불포화수리전도도(不飽和水理傳導度)와 수분특성곡선(水分待性曲線)을 동시(同時)에 구(求)할 수 있는 방법(方法)을 제안(提案)하기 위하여 Gardner의 유출양법(流出量法)을 변형(變形)하여 soil moisture pressure-plate extractor를 이용(利用)하여 공시토지(供試土壤)에 대(對)하여 실험(實驗)을 수행(遂行)하였다. Cardner의 pressure-plate 유출방정식(流出方程式)을 이용(利用)하여 상이(相異)한 수분장력(水分張力)에서 pressure-plate extractor내(內) 수분함량변화(水分含量變化)로부터 불포화수리전도도(不飽和水理傳導度)를 계산(計算)하였다. 수분장력(水分張力) 30mbar에서 10bar까지 본량(本良) 사양토(砂壤土), 예산(禮山) 미사질양토(微砂質壤土) 및 포곡(浦谷) 식양토(埴壤土)의 불포화수리전도도(不飽和水理傳導度)는 각각(各各) $3.09{\times}10^{-2}cm/day{\sim}4.06{\times}10^{-6}cm/day$, $1.34{\times}10^{-2}cm/day{\sim}7.30{\times}10^{-6}cm/day$ 및 $1.83{\times}10^{-2}cm/day{\sim}8.50{\times}10^{-6}cm/day$로 변(變)하였다. 유출양법(流出量法)과 비교(比較)하여 적당(摘當)한 시간(時間) 간격(間隔)으로 수분정량(水分定量)을 하여야 하고 그때마다 압력(壓力)을 조정(調整)하여야 하는 불편(不便)이 있으나, 동시(同時)에 여러 토양(土壤)의 불포화수리전도도(不飽和水理傳導度)의 계산(計算)이 가능(可能)한 장점(長點)이 있었다. soil moisture pressure-plate extractor내(內) 토양수분함량변화(土壤水分含量變化)로부터 불포화수리전도도(不飽和水理傳導度)의 계산(計算)이 가능(可能)하였다.

• 한국조경학회지
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• 제20권1호
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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.

• 대한지역사회영양학회지
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• 제11권1호
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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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• 제29권9호
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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.

• 한국환경과학회지
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• 제21권6호
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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.

• 한국작물학회:학술대회논문집
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• 한국작물학회 2017년도 9th Asian Crop Science Association conference
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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.

• 한국환경과학회지
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• 제22권1호
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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.

• 생물환경조절학회지
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• 제24권2호
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• pp.119-122
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• 2015

본 연구는 비가림하우스에서 오크라의 적심처리 시기가 오크라 과실의 생육 및 수량에 미치는 영향을 조사하기 위하여 수행되었다. 오크라는 5월에 정식하였으며, 품종은 '그린소드'를 이용하였다. 오크라의 적심처리는 정식후 각각 30, 45, 60일 후에 실시하였다. 오크라의 지상부 생체중은 정식 60일후 적심처리구에서 가장 많았으며, 30일 처리구에서 가장 작았다. 반면, 오크라의 초장과 절간장은 적심처리간에 유의한 차이가 없었다. 오크라의 적심처리 재배는 과실의 수량과 수확개수 증가에 효과적이었다. 오크라 과실의 수량은 정식 60일후 적심처리구에서 4,257kg/10a으로 가장 많았으며, 반면 30일후 적심처리구에서 2,508kg/10a으로 가장 적었다. 또한 오크라 과실의 무기성분은 적심처리에 따른 유의한 차이가 없었다. 따라서, 오크라의 비가림재배시 적정한 적심처리 시기는 정식 60일후에 적심처리하는 방법이 가장 적합하였다.

• 대한치과교정학회지
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• 제42권5호
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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.