• Asian-Australasian Journal of Animal Sciences
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• 제9권6호
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• pp.667-670
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• 1996

Four Murrah male buffalo calves with an average body weight of $188{\pm}1.6kg$ each fitted with rumen and abomasal cannula were subjected to defaunation followed by refaunation. The animals were offered wheat straw and a concentrate mixture. There was no difference in dry matter, starch and nitrogen intake in defaunated and refaunated buffalo calves. Production of ruminal total volatile fatty acid and acetate : propionate ratio decreased (p < 0.01) whereas, molar proportion of propionate increased (25.8 Vs 19.4% p < 0.01) in defaunated animals. Fermentation of starch in rumen increased (73.9 Vs 65.8%, p < 0.01) but in small intestine decreased (20.2 Vs. 28.2%, p < 0.05) in defaunated calves. The flow of non ammonia nitrogen (NAN) to abomasum (75.1 vs 68.6 g/d, p < 0.01) and its digestion in small intestine (37,6 vs 32.5 g/d, p < 0.01) was improved due to defaunation. However, No difference in the total tract digestibility of starch and nitrogen was found in defaunated and refaunated buffalo calves.

• Asian-Australasian Journal of Animal Sciences
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• 제22권1호
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• pp.72-81
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• 2009

Eight Black Belly rams (45.2 kg) fitted with permanent ruminal cannulae were used in a 2${\times}$2 factorial design to determine the effects of feeding frequency and regrowth age on intake and digestion. Rams were fed with 21- or 35-day old fresh pangola grass offered ad libitum two or four times a day. Irrespective of the regrowth age, there was a tendency for intake to be positively correlated with increase in meal frequency. Differences were not significant (p>0.25). Significant effects of meal frequency were observed in NDF and ADF total tract digestibility of the 35-day grass which decreased as the number of meals increased. Meal frequency had no visible effect on feeding behaviour. Total rumen content increased when animals were fed twice a day as opposed to four times a day. Similarly, an accumulation of small and very small particles was observed in the rumen of rams fed twice a day in comparison with those fed four times a day. These results suggest that studies of digestive dynamics performed at a steady state are not representative of the rumen loading observed in farm rams which have two important peaks of meal.

• 상하수도학회지
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• 제17권4호
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• pp.559-566
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• 2003

From this research, the performances of a sludge reduction in the sewage sludge aerobic digestion was experimented by using a sludge pretreatment and membrane bioreactor. The submerged plate membrane was used as the solid-liquid separation membrane. After drawing small amounts of sludge in a bioreactor and then doing the alkaline treatment and ozone treatment, the sludge was sent to back to the reactor. The HRT in the reactor was set as 5 days and the operation in the reactor was carried out at the DO of 1mg/L on average. After 100 days of operation in the reactor, it was shown that the reduction efficiency of total solids was more than 83%. Most of volatile solids were removed through mineralization, and the considerable portion of the non-volatile solids was dissolved and then flowed out with the effluent. Only about 16.3% of total solids in the sludge was accmulated in the reactor even without the loss of volatile fraction. Also, by deriving nitrification and denitrification in one reactor simultaneously, more than 90% of nitrogen removal effect was realized and the experiment was run smoothly without fouling of membrane, even in the high concentration of MLSS. Based on this experiment, sludge can be reduced considerably at a low HRT by these two newly suggested approach.

• 한국수소및신에너지학회논문집
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• 제27권5호
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• pp.533-539
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• 2016

This study was performed to evaluate the characteristics of start-up of anaerobic digestion from food waste with different inoculum ratios. The hydrogen yield was similar with different inoculum ratios. The hydrogen production rate increased with increasing inoculum ratio. But the specific hydrogen production rate decreased with increasing inoculum ratio. Total volatile fatty acids composition analysis showed that butyrate and acetate were the prevalent products in all reactors, followed by lactate and propionate. The acetate was most prevalent product in reactors at $X_0/S_0=0.080$ and 0.159. But in reactors at $X_0/S_0=0.239$ and 0.318, butyrate accounted for greater than 50% of the total volatile fatty acids.

• 한국농공학회논문집
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• 제63권3호
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• pp.35-45
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• 2021

Digestate or slurry produced from anaerobic digestion is mostly applied to crop lands for its disposal and recovering nutrients. However, minimizing nitrogen losses following field application of the digestate is important for maximizing the plant's nitrogen uptake and reducing environmental concerns. This study was conducted to assess the effects of three different biogas digestate application techniques (sawdust mixed with digestate (SSD), the hole application method (HA), and digestate injected in the soil (SD)) on nitrate leaching potential in the soil. A pot laboratory experiment was conducted at room temperature of 25 ± 2 ℃ for 107 days. The experimental results showed that sawdust application method turned out to be appropriate for quick immobilization of surplus N in the form of microbial biomass N, reflecting its lower total nitrogen and NH₄-N contents and low pH. The NH₄-N and total nitrogen fate in the soil fertilized with manure showed no statistically significant (p > 0.05) differences between the different methods applied during the incubation time under room temperature. In contrast, NO₃-N concentration indicates significant reduction in sawdust treatment (p < 0.05) compared to the control and other application methods. However, the soil sawdust mixed with digestate was more effective than the other methods, because of the cumulative labile carbon contents of the amendment, which implies soil net N immobilization.

• 한국식품영양과학회지
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• 제13권1호
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• pp.97-106
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• 1984

남대양(南大洋)에 다량 서식하고 있는 중요한 단백질자원(蛋白質資源)인 크릴을 보다 유효하게 식량(食糧)으로 이용하기 위한 방안의 하나로 크릴을 원료로 하여 그 자체에 존재하는 활성이 높은 자가소화효소(自家消化酵素)나 단백질분해효소(蛋白質分解酵素)로써 크릴간장 제조(製造)를 시도(試圖)하였다. 마쇄한 크릴에 동량(同量)의 물을 첨가하여 가수분해(加水分解)시킬 때의 최적가수분해조건(最適加水分解條件) 및 저장안정성(貯藏安定性)을 검토(檢討)하고 아울려 제품의 정미성분(呈味成分)을 분석(分析)하였다. 자가소화(自家消化)에 의한 경우와 bromelain, complex enzyme을 첨가한 시료(試料) 모두 $52.5^{\circ}C$에서 최대활성을 나타내었고, 분해시간(分解時間)은 3시간(時間)이 적합하였으며, 효소농도(醴素濃度)는 bromelain의 경우 0.5 %, complex enzyme은 5%가 가장 좋았다. 그리고 pH는 자가소화(自家消化)나 complex enzyme을 첨가하여 분해(分解)하였을 경우는 7.0${\sim}$7.5, bromelain을 첨가하여 분해(分解)하였을 때는 6.5부근에서 가장 활성이 높았다. 이와 같은 최적가수부해조건(最適加水分解條件)에서 크릴을 자가소화(自家消化)시킨 후 $100^{\circ}C$, 20 분간(分間) 불활성화한 다음 여과한 가수분해물(加水分解物)에 식염(食鹽)(10 %)과 벤조산(0.06%)이나 알코올(3 %)을 첨가하여 멸균한 유리병에 밀봉(貯減)한 결과 $37^{\circ}C$에서 한달간 저장(貯藏)하여도 화학적, 미생물적 및 관능적으로 안정하였다. 또한 관능적인 맛으로 보아 식염(食鹽) 10 % 중 5 % 정도까지는 나트륨염(鹽) 대신 칼륨염(鹽)을 대체 첨가할 수 있었다. 크릴간장의 단백질가수분해율(蛋白質加水分解率)은 자가소화법(自家消火法)인 경우 83.2%, bromelain 첨가구는 89.7%, complex enzyme 첨가구는 92.7 %이었다. 자가소화법(自家消化法), bromelain 또는 complex enzyme첨가에 의해 제조(製造) 된 크릴간장의 유리(遊離)아미노산(酸) 중 함량이 많은 것은 lysine, arginine, leucine, proline, alanine 및 valine으로서 전 유리(遊離)아미노산(酸)에 대해 각각 58.8 %, 56.0 %, 55.3 %를 차지하였다. 그리고 전엑스분망(分望) 소(素)에 대하여 유리(遊離)아미노산(酸)이 차지하는 비율은 각각 67.4 %,69.4%, 69.8 %이었다. 핵산관련물질(核酸關聯物質) 중 함량이 가장 많은 것은 hypoxanthine이었고, 다음이 5’-IMP였다. TMAO, betaine, 총 creatinine은 함량이 적었다. 관능검사결과(官能檢査結果) 자가소화(自家消化)시킨 크릴간장은 효소(酵素)처리한 것이나 재래식 콩간장에 비하여 품질 면에서 손색이 없고 저장성(貯藏性)이 좋은 크릴간장을 제조(製造)할 수 있다는 결론을 얻었다.

• KSBB Journal
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• 제15권4호
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• pp.411-413
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• 2000

본 연구에서는 Lactobacillus crispatus KLB46의 genomic DNA를 빠르고, 간단하게 소량 (3 mL)의 배양액에서부터 추출하는 방법을 확립하였다. 이 방법을 이용하여 L. crispatus KLB46로부터 total genomic DNA를 분리한후 peR과 제한효 소처리를 하여 전기영동으로 확인하였다. 질의 정상세균총을 이루고 병원성균의 증식을 억제하는 그램양성균인 L. crispatus KLB46의 genomic DNA의 신속한 추출방법은 이 균주의 유 전공학연구에 유용하게 사용될 수 있을 것으로 기대된다.

• 환경위생공학
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• 제15권4호
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• pp.84-90
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• 2000

5L laboratory-scale anaerobic digester was used to study the effects of food size and washing rate of food waste on the mixed digestion with sewage sludge. Food waste was crushed with particle diameters of 4mm and 2mm and washed two to three times, and seven to eight times before feeding the batch digester. The digester with crushed of washed food waste showed better performance than that with uncrushed of unwashed to produce methane gas of reduce volatile solids. The digester with 2mm food waste showed 17.4% higher VS/TS reduction rate and 18ml higher methane production rate per gram VS input than that with uncrushed food waste, where VS and TS are volatile solid and total solids in the liquid effluent, respectively. Also food waste crushed eight times gave 8% higher VS/TS reduction rate and 11ml higher methane production rate per gram VS input than unwashed food waste.

• 상하수도학회지
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• 제24권4호
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• pp.395-406
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• 2010

In this study, anaerobic digestion, electro-oxidation and electro-fenton oxidation processes were investigated to reduce oily refinery sludge. Anaerobic digestion process was not suitable for oily activated sludge reduction because of characteristics itself and, as experimental results revealed, reduction efficiency was low for electro-oxidation process. However, 40% total suspended solid reduction of oily activated sludge was obtained by electro-fenton oxidation process, operating at pH=1, 0.5 A and $Fe^{2+}$:$H_2O_2$ ratio = 1:30. In addition, higher reduction efficiency was obtained as reaction time was increased (30, 60, 90, 120 min) despite of low $H_2O_2$ concentration. From the results, it has been investigated that electro-fenton oxidation is efficient process for oily activated sludge reduction.

• 한국축산시설환경학회지
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• 제19권2호
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• pp.191-196
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• 2013

In this study, the mixture ratio included 20% (GLY 20), 40% (GLY 40), and 60% (GLY 60) based on VS with the control group (GLY 0) with no crude glycerin added. Maintaining stable pH, GLY 20 and GLY 0 showed the highest total output of biogas (1.24 L/L/d) and methane(0.78 L/L/d) as its volatile solids reduction rate was 53.56%. In case of GLY 40 and GLY 60, their pH was rapidly reduced after seven days of the study, so that their anaerobic digestion was all stopped.In the results of the study, it is desirable to add crude glycerin less than 20%, and it would be necessary to have the future researches on more detailed organic loading rate of each ratio, and analysis on economic feasibility.