• KSBB Journal
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• 제5권3호
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• pp.235-240
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• 1990

Pseudomonas elodea 에 의한 Gellan gum생산시 이에 관련된 기초자료를 얻기 위하여 회분식 및 연속식 발효를 하였다. 회분식 배양의 결과로부터 비성장 속도는 $0.16hr^-^1$이었으며 72시간 배양후의 점도는 4500cp, 생성물 농도 0.7g dry weught/100g broth, 및 생산성은 0.08g dry weight/1/hr이었다. 연속식 배양을 통하여 최적 탄소원과 질소원의 농도비(3.0mg-carbon/mg-nitrogen)를 결정하였으며 Gellan gum의 최대 생성속도는 희석율 $0.14hr^-^1$에서 0.6g dry weight/l/hr이었다. 이러한 조건에서 각종 metabolic paeameter값을 계산하였다. 또한 배양액의 유변학적 특성은 Casson equation에 잘 부합됨을 확인하였고, 배양액의 점도와 산소전달계수를 측정하여 고점도 배양시 산소전달의 장애현상을 조사하였다.

• 한국농공학회논문집
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• 제48권3호
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• pp.97-106
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• 2006

The pollutant concentrations at experimental paddy plots with three (excessive, standard, reduced) different fertilization rates were investigated during 2001-2002 irrigation seasons. Mean concentrations of pollutants in ponded water were not significantly different among three experimental plots, but the T-N concentrations in percolated water significantly depended on fertilization rates. The T-N, T-P and $COD_{Cr}$, concentrations in ponded water during early irrigation season (late May to mid-June) were much higher than those during later irrigation season likely due to fertilization and low uptake by young rice crops. The T-N concentrations decreased but the concentrations of T-P and $COD_{Cr}$, increased three days after tillering fertilization. The removal rates of T-N by paddy plots were $0.13-0.16g/m^2{\cdot}d$ for an excessive fertilization plot, $0.08-0.25g/m^2{\cdot}d$ for a standard fertilization plot, and $0.03-0.34g/m^2{\cdot}d$ for a reduced fertilization plot three days after tillering fertilization. On the other hand, T-P and $COD_{Cr}$, were released three days after tillering fertilization.

• 한국토양비료학회지
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• 제43권3호
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• pp.349-355
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• 2010

본 연구는 토양검정시비량에 준하는 비료량을 기준으로 그 처리량을 가감하여 점적관수로 관비하였을 경우 참외의 생육과 수량에 미치는 영향을 조사하고 참외의 생육단계별 양분흡수특성을 검토하여 관비재배 시에 생육단계별 참외 질소시비기준을 설정하고자 수행되었다. 이를 위하여 토양검정 질소시비량 ($N:P_2O_5:K_2O$=249:408:315 kg $ha^{-1}$)의 0배, 0.5배, 1.0배, 1.5배에 해당하는 질소량을 8회로 나누어 정식 후 10일 간격으로 관비하였다. 점적관비에 의한 참외 생육기간 중 참외의 생육, 수량 및 무기양분흡수 등을 조사하였다. 잎, 줄기 중 T-N의 함량은 정식 30일까지 증가한 후 점점 감소하는 경향을 보였고, 질소관비량이 증가할수록 T-N함량도 증가하는 경향을 볼 수 있었다. 질소관비량이 증가할수록 참외의 생체중과 질소흡수량은 증가하였지만 총수량 및 상품수량은 그렇지 않았다. 총수량과 상품수량은 검정시비 0.5배구에서 각각 44,550 kg $ha^{-1}$와 42,880 kg $ha^{-1}$로 가장 높았다. 또 상품과율도 0.5배구에서 95%로 가장 높았다. 결과적으로 과실의 총수량, 상품수량, 상품과율 등을 고려할 때, 검정시비 0.5배구에 해당하는 질소량의 관비가 참외의 생육 및 수량 증가에 가장 효과적인 것으로 판단된다.

• 한국작물학회지
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• 제30권2호
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• pp.140-145
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• 1985

퇴비시용량 (0, 1,500kg/10a) 및 질소시비량 (0, 5, 10, 15, 20kg/10a)과 질소반양추비(1982년, 15, 20kg/10a의 경우)에 따른 단옥수수 Sun glow(1982년 공시) 및 Honey Bantam-9 (1983년 공시)의 생육 및 수량성은 다음과 같다. 1. 퇴비시용은 이삭의 크기를 증대시켰고 10a당이삭무게를 약 10％ 증가 시켰다. 2. 10a당 이삭수는 10a당 질소 10kg까지 증비할 때는 크게 증가하였고 이삭무게는 무퇴비구에서는 10a당 질소 20kg까지도 증수되었으나 퇴비시용구에서는 10a당 질소 10kg 까지만 큰 증수를 보였다. 3. 10a당 지상부 건물수량은 무퇴비구에서는 10a당 질소 15kg, 퇴비시용구에서는 질소 10kg까지 크게 증가 되었다. 4 지상부 질소흡수량은 무질소에서 8.1kg였고 10a당 질소 20kg 시용에서 18.8kg로 질소시비량 증가에 따라 직선적인 증가 경향이었다. 5 10a당 이삭수, 이삭무게, 건물중 등을 고려한 적정 질소시비량은 10a당 10-15kg로 보여진다. 6, 질소추비의 효과는 이삭크기, 10a당 이삭수 및 이삭무게 등에서 인정되지 않았다.

• 한국환경과학회지
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• 제19권5호
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• pp.647-653
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• 2010

The objectives of this research are to evaluate and compare the oxygen transfer coefficients($K_{La}$) in both a general bubbles reactor and a micro-nano bubbles reactor for effective operation in sewage treatment plants, and to understand the effect on microbial kinetic parameters of biomass growth for optimal biological treatment in sewage treatment plants when the micro-nano bubbles reactor is applied. Oxygen transfer coefficients($K_{La}$) of tap water and effluent of primary clarifier were determined. The oxygen transfer coefficients of the tap water for the general bubbles reactor and micro-nano bubbles reactor were found to be 0.28 $hr^{-1}$ and 2.50 $hr^{-1}$, respectively. The oxygen transfer coefficients of the effluent of the primary clarifier for the general bubbles reactor and micro-nano bubbles reactor were found be to 0.15 $hr^{-1}$ and 0.91 $hr^{-1}$, respectively. In order to figure out kinetic parameters of biomass growth for the general bubbles reactor and micro-nano bubbles reactor, oxygen uptake rates(OURs) in the saturated effluent of the primary clarifier were measured with the general bubbles reactor and micro-nano bubbles reactor. The OURs of in the saturated effluent of the primary clarifier with the general bubbles reactor and micro-nano bubbles reactor were 0.0294 mg $O_2/L{\cdot}hr$ and 0.0465 mg $O_2/L{\cdot}hr$, respectively. The higher micro-nano bubbles reactor's oxygen transfer coefficient increases the OURs. In addition, the maximum readily biodegradable substrate utilization rates($K_{ms}$) for the general bubbles reactor and micro-nano bubbles reactor were 3.41 mg COD utilized/mg active VSS day and 7.07 mg COD utilized/mg active VSS day, respectively. The maximum specific biomass growth rates for heterotrophic biomass(${\mu}_{max}$) were calculated by both values of yield for heterotrophic biomass($Y_H$) and the maximum readily biodegradable substrate utilization rates($K_{ms}$). The values of ${\mu}_{max}$ for the general bubbles reactor and micro-nano bubbles reactor were 1.62 $day^{-1}$ and 3.36 $day^{-1}$, respectively. The reported results show that the micro-nano bubbles reactor increased air-liquid contact area. This method could remove dissolved organic matters and nutrients efficiently and effectively.

• 대한핵의학회지
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• 제36권1호
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• pp.8-18
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• 2002

Early and accurate diagnosis of tumors using positron omission tomography (PET) has been the focus of considerable interest due to its high metastasis and mortality rates at late detection. PET radiopharmaceuticals-which exhibit a high tumor-to-background uptake ratio, and appropriate metabolic characteristics, and pharmacokinetics-are attractive tools for tumor imaging. Tumor imaging by these radiopharmaceuticals are based on metabolic and receptor imaging. The former is based on accelerated metabolism in tumor tissue compared to normal tissue and the rate roughly corresponding to the rate of growth of tumors. Radiopharmaceuticals for this purpose include radiolabeled sugars, amino acids, and nucleosides which detect increased glucose utilization, protein synthesis, and DNA synthesis, respectively. Tumor receptor imaging is based on the proliferation of tumor cells regulated by many hormones and growth factors, which bind to the corresponding receptors and exhibit the biological responses Radiopharmaceuticals used to image the tumor receptor systems may be ligands for the specific receptors and antibodies for the growth factor receptors. Some antitumor agents have been labeled with radionuclides and used to study in vivo biodistribution and pharmacokinetics in humans. This overview describes typical PET radiopharmaceuticals used for tumor imaging based on their uptake mechanisms.

• 한국작물학회지
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• 제44권1호
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• pp.44-48
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• 1999

Uptake, assimilation and translocation of nitrogen and dry matter assimilation and translocation in ten rice cultivars were observed in no-till direct-sown rice-vetch cropping system. There was a large degree of variation in N-uptake, grain yield, nitrogen translocation efficiency and dry matter assimilation and translocation in tested rice cultivars. Forty kg N/ha base, as compound fertilizer (21-17-21% of N-P-K) three weeks after sowing and 30 kg N/ha top-dressed at panicle initiation stage as in the form of (NH$_4$)$_2$$CO_2$ was applied. ‘Newbounet’, ‘Daesanbyeo’, and ‘Hwayeongbyeo’ showed higher translocation efficiency. The contribution of pre-heading dry matter assimilates to grain ranged from 33% to 99% of dry grain weight. Dry matter of ‘Calrose 76’ was lower than Newbounet but N content was higher in Calrose 76 than Newbonnet. By maturity, N content in vegetative parts declined considerably more than dry matter, vegetative and reproductive parts, N translocation efficiency, and N harvest index. Nitrogen translocation efficiency was greater in ‘Nonganbyeo’, Daesanbyeo, and Newbounet. Grain N concentration was positively correlated with N concentration or N content of the vegetative parts at heading in Nonganbyeo, ‘Dasanbyeo’, ‘Dongjinbyeo’, and Newbonnet. These results indicated that the greater amount of dry matter and N accumulated before heading stage, the higher translocation rates of dry matter to grain and the greater net losses at maturity.

• Journal of Korean Society for Atmospheric Environment
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• 제21권E2호
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• pp.41-48
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• 2005

A novel hybrid system composed of a biotrickling filter and an activated sludge reactor was investigated under the conditions of four different SRTs (sludge retention times). The performance of the hybrid reactor was found to be directly comparable among the four different sludge ages. Discernible differences in the removal performance were observed among four different SRTs of 2, 4, 6, and 8 days. High removal efficiency was achieved by continuous circulation of activated sludge over the immobilized mixture culture, which allowed on pH control, addition of nutrients, and removal of paint VOCs (volatile organic compounds). The results also showed that the removal efficiency for a given pollutant depends on the activity of microorganisms based on the SRT. As the SRT increased gradually from 2 to 8 days, the average removal performance decreased. The highest removal rate was achieved at the SRT of 2 days at which the highest OUR (oxygen uptake rate), $6.1mg-O_2/liter-min$ was measured. Biological activity in the recycle microbes decreased to a much lower level, $3.6mg-O_2/liter-min$ at a SRT of 8 days. It is thus believed that young microorganisms were more active and more efficient for the VOCs removal of low concentrations and high flow rates. The apparent correlation of $R^2=0.996$ between the average removal efficiency and the average OUR at each SRTs suggests that VOCs degradation by young cells significantly affected the overall removal efficiency for the tested SRTs.

• 한국식품과학회지
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• 제19권2호
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• pp.125-128
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• 1987

압맥, 할맥 및 보리쌀을 $20{\sim}$50^{\circ}C$의 물에 6시간 침지 시키면서 수분흡수속도를 비교하였다. 압맥은 할맥보다 할맥은 겉보리에 비하여 높은 수분흡수를 나타내었으며 온도가 높아질수록 수분흡수속도가 증가하였고 압맥이 온도 의존성이 가장 높았다. 또한$100^{\circ}C$에서 가열시 호화완료 시간은 압맥이 할맥 및 보러쌀 보다 각각 1.4배 및 2배 빨랐다.

• Journal of Biosystems Engineering
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• 제29권6호
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• pp.508-514
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• 2004

This study was conducted to investigate the influences of aeration rates and temperatures on phosphorus transformation in the manure during treatment of swine manure in 15.3L batch reactor. The total phosphorus of raw manure was composed of $91.5\%$ of inorganic phosphorus and $8.5\%$ of organic phosphorus. During the experiment, inorganic phosphorus decreased from $91.5\%\;(385.7\;mg/L)\;to\;25.8-42.7\%\;(108.8-179.8\;mg/L)$ while organic phosphorus increased from $8.5\%\;(35.6\;mg/L)\;to\;57.3-74.2\%\;(241.5-312.5\;mg/L)$. The organic phosphorus was increased by the possible transformation of soluble inorganic phosphorus to poly-phosphate by the microbial uptake. However, soluble inorganic phosphorus was not decreased much during the experiment because the insoluble inorganic phosphorus was transferred to soluble inorganic phosphorus offsetting the microbial uptake. There was no significant difference in soluble inorganic proportion variance during the experiment among treatments for three liquid temperatures and three aeration levels. In terms of phosphorus transformation in the manure and energy consumption required for aeration, lower aeration was desirable fur the manure treatment.