• Journal of Biosystems Engineering
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• 제37권2호
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• pp.100-105
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• 2012

Purpose: Methane production potential in aerobic digestion was assessed according to feed to inoculum (F/I) ratio for food waste only, and mixing ratio of two materials for food waste and swine manure to give a basic data for the design of anaerobic digestion system. Methods: Anaerbic digestion test was performed using a lab scale batch reactor at $35^{\circ}C$ for six different feed to inoculum (F/I) ratios (0.50, 0.72, 1.14, 1.50, 2.14 and 3.41), three food waste to swine manure ratios (100:0, 60:40 and 40:60) with two different loading concentrations (10g VS/L and 30g VS/L). Results: For food waste only, the highest biogas yield of 1008 mL/gVS was obtained at 0.50 of F/I. For the co-digestion of food waste and swine manure mixture, the highest biogas yield of 1148 mL/gVS was obtained at a mixing ratio of 40:60 with loading concentration of 10g VS/L. Conclusions: F/I ratio for the food waste only, mixing ratio of food waste and swine manure, and co-substrate loading rate affected the biogas production rate. For the low loading rate, there was not so much difference according to the mixing ratio of food waste and swine manure, but for the high loading rate higher biogas yield was acquired for the co-digestion of food waste and swine manure than for the food waste alone (mixing ratio, 100:0).

• 한국연초학회지
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• 제26권2호
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• pp.73-78
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• 2004

This study was conducted to find out the relationship among agronomic characteristics including midrib ratio in Burley tobacco(N.tabacum L.) Four cultrivars, Burley 21, KB108, KB111 and KB301, were grown at Suwon Experimental Station in 2001. Several agronomic characteristics of these cultivars were measured for the analysis of correlations among agronomic characteristics. Midrib ratio of KB301 was somewhat higher than those of the other cultivars, but there is no significant differences among cultivars at $5\%$ probability level. Among four stalk positions, midrib ratio of cutters was the highest. Midrib ratio was correlated positively with length of leaf at $1\%$ level and negatively with weight of lamina at $5\%$ level, respectively.

• 한국추진공학회지
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• 제9권4호
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• pp.31-38
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• 2005

본 연구에서는 단일 포트 연료 형상을 갖는 하이브리드 추진 시스템의 고체 연료의 L/D(길이/직경)비 변화에 따른 연소 특성을 고찰하였다. 본 연구를 위해 연료 포트 직경이 같은 경우와 연료 길이가 같은 경우로 나누어 L/D 비 변화에 관한 실험을 수행하였다 연료 포트 직경이 같은 경우 L/D 비 변화에 따른 후퇴율은 큰 차이가 없었으며 L/D 비가 클수록 O/F 비는 낮았고 추력과 특성속도는 높았다. 연료 길이가 같은 경우 L/D 비 변화에 따른 O/F 비와 추력, 특성속도는 큰 차이가 없었으며 L/D 비가 작을수록 후퇴율은 높았다. O/F 비의 변화가 없을 경우 $\dot{r}=a{G_0}^n$에서 지수 n은 0.5의 값을 갖는 것을 실험적으로 얻을 수 있었다. PE와 기체산소를 본 실험의 연료와 산화제로 사용하였다.

• 한국식품영양과학회지
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• 제34권10호
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• pp.1625-1632
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• 2005

양배추(홍월적) 추출물의 추출수율과 기능성을 최적화하고자 반응표면분석법을 이용하여 모니터링하였다. 추출조건에 따른 수율의 최대값은 44.47$\%$로 시료에 대한 용매비 25.58 mL/g, 에탄올 농도 56.84$\%$ 및 추출온도 79.86$^{\circ}C$였으며, 전자공여능의 최대값은 85.46$\%$로 시료에 대한 용매비 27.71 mL/g, 에탄올 농도 57.06$\%$ 및 추출온도 46.38$^{\circ}C$일 때였다. 또한 tyrosinase 저해효과는 시 료에 대한 용매비 16.03 mL/g, 에탄올 농도 47.71$\%$및 추출온도 37.50$^{\circ}C$일 때 최대값 69.37$\%$를 나타내었다. 아질산염 소거능은 pH 1.0에서 가장 높은 값을 나타내었으며, 최대값은 99.52$\%$이었으며, SOD 유사활성의 최 값은 48.36$\%$로 이 때의 추출조건은 시료에 대한 용매비 29.13 mL/g, 에탄올 농도 70.35$\%$ 및 추출온도 66.12$^{\circ}C$였다. 조건별 추출물의 수율, 전자공여능, SOD 유사활성에 대한 4차원 반응표면을 superimposing하여 얻은 최적 추출조건 범위는 시료에 대한 용매비 20$\∼$30 mL/g, 에탄올 농도 25$\∼$85$\%$, 추출온도 40$\∼$90$\%$로 나타났다.

• 한국생물공학회:학술대회논문집
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• 한국생물공학회 2000년도 춘계학술발표대회
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• pp.271-274
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• 2000

A study was carried out to select a nitrogen source and the optimize the C/N ratio for the maximum cell growth of Phaffia rhodozyma in fed-batch culture. The yeast extract was the best organic nitrogen source. In the batch culture experiments, the highest cell yield was obtained 0.575 g-cell/g-glucose from 10 g/L and 10 g/L yeast extract. In the fed-batch experiments, the maximum cell concentration was obtained 33.1 g/L from the C/N ratio of 2:1 while the astaxanthin concentration of cell was Increased by increasing the C/N ratio, of feed medium.

• 한국생물공학회:학술대회논문집
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• 한국생물공학회 2005년도 생물공학의 동향(XVI)
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• pp.65-66
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• 2005

Anaerobic digestion is one of the well-known methods for biological treatment handling of concentrated organic matter such as swine $wastewater.^{1)} The anaerobic digestion can reduce organic loading but also hydrolyze non-biodegradable organic $matter.^{2)}$ The feces from the scrapper-type barn are usually collected to make compost and the urine is discarded with swine-slurry wastewater by ocean-dumping or treated by biological methods. The lagoon, aerobic digestion, anaerobic digestion, SBR, $A^{2}/O$, and UCT have been applied for treating swine $wastewater.^{3)} In this study, as a result of the analysis of swine wastewater, the total and soluble chemical oxygen demand was 130g/L and 60g/L, respectively. And the volatile fatty acid as chemical oxygen demand equivalent was 45g/L, which was 75% of soluble chemical oxygen demand. Before everything else, ammonia nitrogen concentration was 6.5 g/L. From biochemical acidogenic potential test, it was concluded that the enhanced acidification process to manage swine waste should be operated in the ammonia nitrogen concentration of less than 1.2 g/L. In the result of seeding ratio experiments with artificial $wastewater^{4)}, the lag period of acidogens was taken the long time because of the inhibition by the $ammonia^{5)}$, however no difference of period by the seeding ratio was not shown. The Haldane-based biokinetics were also evaluated using a method of fourth order Runge-Kutta $approximation.^{6,7)}$ The nonlinear least squares (NLLS) method with a 95% confidence interval was also used. The ranges of maximum microbial growth rate, ${/mu_{max}}$, and half saturation coefficient, $K_{s}$, for acidogenesis of various seeding ratio with artificial wastewater were 6.1 ~ 12.6 $d^{-1}$ and 45,000 ~ 53,500 mg glucose/L, respectively. Also, the methanogenic microbial yield coefficient, Y, and microbial decay rate coefficient, $k_{d}$, and inhibition substrate concentration, $K_{si}$, for the reactors were determined to be 0.32 ~ 0.465 ${/mu}g$/mg glucose; 0.42 ~ 1.01 $d^{-1}$ and 51,500 ~ 55,600 mg glucose/L, respectively.

• 한국미생물·생명공학회지
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• 제19권4호
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• pp.419-427
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• 1991

에탄올의 발효 생산성을 높이기 위해서는 발효조의 균체농도를 높여 고농도의 배양을 해야하며 또한 에탄올에 의한 저해 작용을 감소시켜 비생산성을 향상시키기 위해서는 발효액 중에 축적되는 에탄올을 배출 시킬 필요가 있다. 이와 같은 목적으로 본 연구에서는 고분자 hollow fiber membrane, ceramic filter를 이용하여 가장 중요한 조작 변수인 희석율과 bleed stream ratio가 에탄올 생산성에 미치는 영향 및 조작의 문제점과 장기 조업 가능성을 검토하였다.

• 한국물환경학회지
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• 제21권6호
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• pp.687-694
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• 2005

Lab-scale experiments have been carried out to investigate the effect of F/R ratio of ASBR (Anaerobic Sequencing Batch Reactor) process on the removal of the organic matters in ammonia stripped swine wastewater. Three ASBR inoculated with sludge mixed with granular sludge of UASB (Upflow Anaerobic Sludge Blanket) and anaerobic digested sludge of municipal wastewater treatment plant were operated. Ammonia stripped swine wastewater was used as influent. Prior to conducting the experiments with varied conditions, the effect of increasing organic loading rate from 2.34 to $5.79gTCOD_{Cr}/L$-day at a fixed F/R ratio of 0.1 on the organic removal efficiency has been studied during start-up period. As the result of the experiment, under the condition of varied organic loadings, less than $4.14gTCOD_{Cr}/L$-day, the removed efficiency $TCOD_{Cr}$ of the ASBR process is 83% resulted from the mean value of effluent $TCOD_{Cr}$, 9,125 mg/L during the start-up period. Then ASBRs were operated with F/R ratio of 0.024, 0.303 and 0.91 respectively. Organic loading rate was increased from 4.56 to $15.43gTCOD_{Cr}/L$-day to investigate the effects of F/R ratio and organic loading rate on the organic removal efficiency. As the result of the experiment, less than $6.23gTCOD_{Cr}/L$/L-day, F/R ratio haven't an effect on the organic removal efficiency and the mean removal efficiency of TSS, $TCOD_{Cr}$ and $SCOD_{Cr}$ was about 80%, 86% and 78% at the all of F/R ratio. But as organic loading rate was increased from 8.54 to $12.04gTCOD_{Cr}/L$-day at the F/R ratio of 0.024, the removal efficiency of $SCOD_{Cr}$ decreased from 71% to 63%. The range of decreased removal efficiency of $SCOD_{Cr}$ at the F/R ratio of 0.024 was much more higher than at the F/R ratio of 0.303, 0.91. Thus, as organic loading rate was increased, ASBRs were operated with high F/R ratio to obtain high removal efficiency.

• KSBB Journal
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• 제16권2호
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• pp.140-145
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• 2001

To treat piggery wastewater containing refractory compounds including nitrogen, physical treatments using zeolite and biological processes were investigated. In biogical treatment, the removal efficiencies of organics and nitrogen in bioreador using BACC (Biological Activated Carbon Cartridge) media filled with granule activated carbon were examined. The best removal efficiencies achieved for TKN and COD(sub)cr were 82% and 53% respectively, when zeolite dosage was 300 g/L. Specific nitrogen removal ability was 3.2 mg/g at a zeolite dosage of 50 g/L, whereas specific nitrogen removal ability was 1.8 mg/g at a zeolite dosage of 300 g/L. The increased of C/N ratio resulting from the removal of nitrogen using zeolite led to an increase in removal efficiency of organics. As C/N ratio was increased to 2.0, 2.44 and 6.58 at a HRT of 48 hours in a BACC bioreactor, removal efficiencies of COD(sub)cr were increased to 53.5%, 57.4% and 80.6%. The removal efficiency of wastewater using a zeolite dosage of 399 g/L was increased by 27.1% compared to that of control treatment.

• 한국식품저장유통학회지
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• 제15권1호
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• pp.111-117
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• 2008

본 연구에서는 도토리를 이용한 기능 식품개발을 목적으로 한 연구의 일환으로 도토리의 항산화 특성을 조사하기 위하여 추출온도 $30{\sim}70^{\circ}C$, 추출시간 $1{\sim}5$ 시간, 용매비 $5{\sim}25$ mL/g을 중심합성계획법으로 16개의 구간으로 하여 총페놀성 화합물의 함량, 전자공여능, 항산화능 및 아질산 염소거작용 등을 반응표면분석법으로 모니터링하여 최적추출조건을 설정하였다. 실험 결과 총페놀성 화합물 함량은 추출온도 $57.91^{\circ}C$, 추출시 간 4.08 시간 및 시료에 대한 용매비 22.39 mL/g에서 최대값을 나타내었으며, 용매비에 영향을 받고 있으며, 추출시간 및 추출온도의 영향은 없는 것으로 나타났다. 전자공여능에 대해서는 추출온도 $60.37^{\circ}C$, 추출시간 2.85 시간 및 용매비 6.47mL/g일 때 최대값을 나타내었으며, 항산화능에서는 최대값이 2.09 AI로 예측되었고, 이때 추출조건은 추출온도 $37.11^{\circ}C$, 추출시간 1.67시간 및 용매비 18.84 mL/g이었으며 추출온도, 추출시간 및 용매비 모두에 대해 영향을 크게 받고 있는 것으로 나타났다. 아질산염소거능은 추출온도 $47.07^{\circ}C$, 추출시간 1.24시간 및 용매비 19.55 mL/g에서 최대값을 나타내었다. 추출 후 아질산염소거능의 변화는 용매비에 영향을 가장 크게 받으며, 다음으로 추출온도에 영향을 받는 것으로 나타났으나 설정 범위내에서 추출시간에 대한 영향은 나타나지 않았다.