• Asian-Australasian Journal of Animal Sciences
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• 제24권3호
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• pp.394-399
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• 2011

The effect of intermittent feeding on growth, feed utilization and body composition of subadult olive flounder fed extruded pellet (EP) in suboptimal temperature ($13.5{\pm}2.10^{\circ}C$) was determined. Two hundred twenty five subadult fish averaging 272 g were randomly distributed into fifteen of 300 L circular flow-through tanks (fifteen fish per tank). Five treatments with different days of feeding a week were prepared in triplicate: fish were hand-fed with EP to apparent satiation once a day, seven days a week (7DF), which was used as the control group or consecutive six, five, four and three days a week, for 12 weeks, referred to as 6DF, 5DF, 4DF and 3DF treatments, respectively. Weight gains and specific growth rates of fish in 6DF treatment were higher than those of fish in 7DF, 4DF and 3DF treatments, but not different from those of fish in 5DF treatment. Daily feed intake of fish in 6DF and 7DF treatments was higher than that of fish in 5DF, 4DF and 3DF treatments. Feed efficiency and protein efficiency ratio of fish were not different among treatments. There was no difference in the chemical composition of fish between treatments. Results of this study demonstrated that feeding five days per week could be recommended for subadult olive flounder fed extruded pellet in suboptimal temperature.

• 한국물환경학회지
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• 제20권3호
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• pp.269-274
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• 2004

The performance of a newly designed wastewater treatment process equipped with an anaerobic and two intermittent aeration tanks operated alternately was investigated. During the experimental period, several types of cyclic operating schedules with different aeration and non aeration time were examined for the optimization. At all modes, the removals of organic matter and SS were highly achieved. With respect to T-N removal, however, the cycle length for aeration on/off affected the efficiencies. At the optimal operating mode, the ORP bending point indicating the disappearance of nitrate was observed. Considering the influent wastewater characteristics and cyclic operating schedules, it can be suggested that T-P removal is much more BOD/T-P ratio and/or its load dependant rather than the aeration on/off time. The results obtained from pilot-scale test showed the competitive advantage of this alternating process through an omission of nitrate recycle and operational flexibility against influent load variations when comparing with other continuous flow processes.

• 대한환경공학회지
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• 제36권1호
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• pp.42-48
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• 2014

본 연구에서는 단일반응조에서 포기/비포기 시간에 따른 하수 내 유기물질 및 질소화합물을 변화양상을 살펴보고자 하였다. 실험 결과 C/N비 3 : 1, 포기/비포기 20/40 min 구간에서부터 90% 이상의 안정적인 유기물 및 질소 제거가 이루어짐을 알 수 있었다. 포기/비포기 구간의 비율을 길게 유지하는 것이 탈질에 더욱 효과적이었으며 이는 비포기 구간을 유지하는 동안 반응조 내 미생물의 군집변화에 기인하는 것으로 판단하였다. PCR-DGGE를 한 결과, 유기물 및 질소화합물의 산화에 관여하는 미생물로 Dysgonomonas mossii strain Melo40, Eubacterium sp. oral clone JN088, Uncultured bacterium clone SPESB2_718과 Bacterium enrichment culture clone LE이 관찰되었고 탈질에 관여하는 미생물은 Uncultured Acidobacteria bacterium clone AKYG487, Lactobacillus harbinensis strain FQ003, Erythrobacter litoralis strain Gi-3, Phytobacter diazotrophicus strain Ls8, Mycobacterium sp. enrichment culture clone GE10037biofNNA로 나타났다.

• 환경위생공학
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• 제13권2호
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• pp.57-65
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• 1998

In this research, Effect of C/N ratio on nutrient removal in intermittently aerated activated sludge system(IAASS) was investigated with dormitary, building and swine wastewater. Three types (2-stage, 4-stage, modified) of IAASS were operated. Time interval of aeration/nonaeration in IAASS was 1hr/1hr. In treatment of Dormitary wastewater(BOD/T-N ratio : 4.4), Building wastewater (BOD/T-N ratio : 3.14) and swine wastewater(BOD/T-N ratio : 3.84), Nitrogen removal efficiency of 80, 70 and 90.4% was achieved, respectively. Nitrogen removal in IAASS was a great influenced on influent C/N ratio, efficient nitrogen removal was achieved at BOD/T-N ratio over 4. In IAASS operation, $\Delta $BOD mg/L/$\Delta $ nitrogen mg/L ratio was about 4-6. Simultaneous removal of organic, nitrogen and phosphorus in IAASS can achieved. And influent organic was efficiently utilized in denitrification. IAASS could be one of the best alternative process for the retrofit of conventional activated sludge system for the removal of nutrients.

• International Journal of Contents
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• 제3권1호
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• pp.14-18
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• 2007

General replacement policy includes document-based LRU or LFU technique and other various replacement policies are used to replace the documents within cache effectively. But, these replacement policies function only with regard to the time and frequency of document request, not considering the popularity of each web site. In this paper, we present the document replacement policies with regard to the popularity of each web site, which are suitable for modern network environments to enhance the hit-ratio and efficiently manage the contents of cache by effectively replacing documents on intermittent requests by new ones.

• KSBB Journal
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• 제6권1호
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• pp.35-43
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• 1991

The production of poly-$\beta$-hydroxybutyrate(PHB) from methanol by batch and fed-batch cultivations of Methylobacterium sp. GL-10 was studied. PHB accumulation was stimulated by the nutrients deficiency including, NH4+, SO42-, and K+. The nitrogen deficiency was the most critical factor for PHB accumulation. In batch cultivation, the maximum cell concentration and PHB content were 1.86g/l and 0.62g/l, respectively, with 1.0%(v/v) of methanol and 0.5g/1 of ammonium sulfate. The mass doubling time of Methylobacterum sp. GL-10 was in the range of 4-5 hrs. The cell growth and PHB accumulation were severely inhibited at the methanol concentration over than 2% (v/v). To overcome methanol Inhibition, constant feeding and intermittent feedillg fed-batch cultivations were adopted, using C/N molar ratio as a control factor. In constant feeding fed-batch process, cell concentration was increased up to 2.67g/1, and PHB yield was enhanced from 0.33 of batch culture to 0.53. The relatively low cell concentration was caused by methanol accumulated in culture broth at late growth phase. To prevent methanol accumulation and to maximize PHB production, DO-state intermittent fed-batch cultivation was attempted. The cell and PHB concentration was reached up to 4.55g/1 and 1.80g/1, respectively. It was possible to maintain methanol concentration low and also to feed nutrient of desired C/N molar ratio.

• Journal of Nutrition and Health
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• 제39권7호
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• pp.661-673
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• 2006

Ssireum, the traditional Korean sport, is very popular at both amateur and professional levels. Ssireum players are prone to be obese which related to the chronic disease in their later life. The purpose of the study was to compare the anthropometric measurements, quality of diet, and blood parameters of Ssireum players with those of subjects who were matched body mass index, gender and age. Participants in the 3 groups, Ssireum players (SP, n=15), regular moderate exerciser (RME, n=15, >3 times /wk, >20 min/time) and intermittent light exerciser (ILE, n=14) groups. Anthropometric measurements included height, weight, fat mass (by Dual energy X-ray absorptiometry), lean body mass, triceps and thigh skin-fold thickness, mid-arm, waist, hip and thigh circumference. Dietary assessments were accomplished using 3-days food records, diet quality index (DQI), dietary variety score (DVS). Blood levels of lipids, leptin and insulin were analyzed. As a results lean body mass and mid-arm circumference were significantly higher in Ssireum players than those of other groups (p<0.01). Total body fat, trunk fat, abdominal skin fold thickness and waist-hip ratio were significantly lower in SP group than those of other groups (p<0.01). DVS were higher however, dietary quality was low in Ssireum players than in other groups. There were no differences among the 3 groups in regard to blood total cholesterol, LDL-cholesterol and glucose levels however, leptin level was low in Ssireum players. These results indicate that Ssireum players had significantly higher lean body mess and lower body fat when these were compared with regular moderate exerciser and intermittent light exerciser. Blood leptin levels of Ssireum players were low but blood lipid profiles were not significantly different.

• Asian-Australasian Journal of Animal Sciences
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• 제33권12호
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• pp.2031-2038
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• 2020

Objective: This study aimed to determine the effect of intermittent feeding and cold water on performance and carcass traits in broiler chickens between 4 to 6 wk of age exposed to daily high temperature. Methods: Broilers were assigned to four treatment groups according to a 2×2 factorial design between 22 to 42 d of age (80 broilers per treatment, 4 replications). Broilers were divided into two main groups as feeding type (ad-libitum [AL] and intermittent [IF] for 6 h daily) and sub-groups as water temperature (normal [NW], 24.9℃ and cold [CW], 16.4℃). Heat treatment was applied between 11.00 to 17.00 h daily between 22 to 42 d of age. Results: Live weight at 6th wk was not affected by feeding type and water temperature, but the live weight was significantly higher in IF chickens at the 5th wk (p<0.05). Average weekly gain of IF broiler chickens were higher compared to AL group at 4, 5, and 6 wk of age (p< 0.05). Although feeding type did not affect feed intake in 4 and 5th wk, feed intake was higher in IF chickens at 6th wk (p<0.01). In addition, feeding type and water temperature did not affect feed conversion ratio and interactions were not significant (p>0.05). Water temperature had no significant effect on heart, liver, gizzard, and abdominal fat percentages (p>0.05). Conclusion: It is concluded that IF increased the average weekly gain in chickens reared under daily heat stress for 6 h between 22 to 42 d of age. IF in hot environmental conditions slightly increased performance without adversely affecting health, welfare, and physiological traits, whereas CW implementation had no significant effect on performance. It can also be said that IF suppresses a sudden increase in body temperature depending on age and live weight.

• 멤브레인
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• 제15권1호
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• pp.70-83
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• 2005

폭기조를 간헐 폭기로 운전하여 호기/무산소(oxic/anoxic) 시간 비율과 무산소 조건에서 호기 조건으로의 전환시 공기세정이 투과플럭스 및 투과압력에 미치는 영향을 조사하였으며, 호기조건에서 무산소 조건으로 전환 시 펌프의 회전력에 의한 흡인압력이 투과플럭스와 투과 압력에 주는 영향을 조사하였다. 또한 긴 슬러지체류시간(SRT; Sludge Retention Time)과 고농도의 MLSS 유지시에 발생하는 미생물 대사산물이 분리막에 미치는 영향과 응집제를 투여하였을 때 분리막에 작용하는 플러스 효과에 대하여 조사하여 보았다. 호기/무산소(oxic/anoxic)의 시간비율에 따른 유기물 및 질소 제거효율을 조사해본 결과 폭기 40 비폭기 20분의 시간배분 조건에서 처리효율이 가장 양호하였으므로 호기/무산소(oxic/anoxic) 조건을 40/20분으로 한 조건(step-7)에서 약품주입 실험을 수행하였다. 액체 명반을 폭기조에 직접 투여할 경우 약품의 농도가 질산화 및 탈질 미생물에 많은 영향을 주는 것을 알 수 있었으며, MBR공정에서 인 1 mg/L를 제거하기 위해서는 약 0.7 mg/L의 액체명반이 필요한 것으로 확인되었다.

• 유기물자원화
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• 제22권3호
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• pp.41-52
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• 2014

본 연구에서는 부정기적 발생 오수의 생분해도 특성 parameters를 현장 시료채취 및 분석실험을 실시하여 조사 및 분석하였으며 결과는 다음과 같다. TCODcr (Total CODcr)의 1,2차 평균 농도는 325.5 mg/L 이며 TCOD 분율은 100% 로 분석되었다. SCODcr (Soluble CODcr)의 1,2차 평균 농도 는 135.9 mg/L 이며 TCOD 분율은 41.8% 로 분석되었다. Ss (Readily biodegradable substrate)의 1,2차 평균 농도는 74.1 mg/L 이며 TCOD 분율은 22.8% 이다. $S_I$ (Soluble inert non-biodegradable substrate)의 1,2차 평균 농도는 61.8 mg/L 이며 TCOD 분율은 19.0% 이다. Xs(Slowly Biodegradable Substrate)의 1,2차 평균 농도는 27.8 mg/L 이며 TCOD 분율은 8.5% 이다. $X_H$의 1,2차 평균 농도는 103.4 mg/L 이며 TCOD 분율은 31.8% 이다. $X_I$ (Particulate inert non-biodegradable substrate)의 1,2차 평균 농도는 58.5 mg/L 이며 TCOD 분율은 18.0% 이다. 따라서 대상 시료의 용존성 생분해 가능 유기물질은 41.8%로 분석되었으며, 이중 생분해가 용이한 분율은 22.8%로 나타났다. 이와 같이 부정기적인 유입 유량으로 인한 유량조정 또는 균등조의 운전으로 유입부하 변동폭에 대한 영향은 크지 않을 것으로 판단된다.