• Asian-Australasian Journal of Animal Sciences
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• 제29권5호
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• pp.753-758
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• 2016

Moisture content influences physiological characteristics of microbes and physical structure of solid matrices during composting of animal manure. If moisture content is maintained at a proper level, aerobic microorganisms show more active oxygen consumption during composting due to increased microbial activity. In this study, optimum moisture levels for composting of two bedding materials (sawdust, rice hull) and two different mixtures of bedding and beef manure (BS, Beef cattle manure+sawdust; BR, Beef cattle manure+rice hull) were determined based on oxygen uptake rate measured by a pressure sensor method. A broad range of oxygen uptake rates (0.3 to 33.3 mg $O_2/g$ VS d) were monitored as a function of moisture level and composting feedstock type. The maximum oxygen consumption of each material was observed near the saturated condition, which ranged from 75% to 98% of water holding capacity. The optimum moisture content of BS and BR were 70% and 57% on a wet basis, respectively. Although BS's optimum moisture content was near saturated state, its free air space kept a favorable level (above 30%) for aerobic composting due to the sawdust's coarse particle size and bulking effect.

• 한국작물학회지
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• 제33권3호
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• pp.222-228
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• 1988

질소시비량(0,10,20,30kg/10a)과 질소분시비율(기비＋분얼비 : 수비가 100 : 0, 80 : 20, 60 : 40)이 일본형 품종(섬진벼)과 통일형 품종(삼강벼)의 생육, 수량, 수량구성요소 및 질소이용효율에 미치는 영향을 요약하면 다음과 같다. 1. 두 품종 모두 분얼수 질소시비율이 증가할수록 많았고, 섬진벼는 정상적인 분얼구상을 보였으나 삼강벼는 최고분얼기후 8월중에 제2의 최고분얼기를 보였다. 또, 섬진벼는 질소분시비율간에 분얼수의 차이가 없었으나 삼강벼는 생육초기에는 기비와 분얼비의 비율이 높을수록, 8월에는 수비비율이 높을수록 분얼수가 많았다. 2. 두 품종 모두 무질소구보다는 질소시용구에서 등숙율을 제외한 수량구성요소 및 수량이 많았다. 질소시비량 간에는 섬진벼는 시비량이 많을수록 주당수수는 다소 증가하였으나 등숙율은 감소하였고, 수당영화수 및 주당영화수, 천립중, 그리고 수량은 차이가 없었다. 삼강벼는 주당수수, 등숙율, 천립중은 차이가 없었으나 수당영화수 및 주당영화수, 그리고 수량은 질소시비량이 많을수록 증가하였다. 3. 질소분시비율 간에 섬진벼는 전량을 기비와 분얼비로만 시용한 구보다 기비, 분얼비, 수비로 분시한 구에서 수당영화수와 천립중은 비슷하였으나 주당수수, 주당영화수, 등숙율, 수량이 높았다. 그러나, 삼강벼는 수비비율이 높을수록 주당수수는 증가하나 수당영화수는 급격히 감소하였고 주당영화수, 등숙율, 천립중, 수량은 큰 차이가 없었다. 4. 두 품종 모두 질소시비량이 많을수록 질소흡수량은 증가하였으나 질소비료의 흡수율은 감소하였다. 흡수된 단위질소당 현미생산량은 질소시비량이 증가할수록 감소하였으나 삼강벼는 차이가 없었다. 5. 질소분시비율 간에는 섬진벼는 수비비율이 높을수록 질소흡수량과 질소비료의 흡수율이 높았고 흡수된 단위질소당 현미생산량은 차이가 없었다. 그러나, 삼강벼는 질소흡수량은 차이가 없었으나 질소비료의 흡수율, 흡수된 단위질소당 현미생산량은 분시비율이 높을수록 감소하였다.

• 한국해양학회지:바다
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• 제16권4호
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• pp.196-205
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• 2011

국내 해조류 양식종인 다시마(Saccharina japonica (Laminaria japonica Areschoug))의 영양염 및 무기탄소 흡수율과 광합성 특성을 살펴보기 위해, 부산시 기장군 일광해역 양식장에서 2011년 l월부터 5월동안 시료를 채집하여 실내 배양하였다. 배양 시료의 엽장과 엽폭 범위는 각각 46~288 cm, 4.8~22.0 cm였으며, 이들의 용존산소 평균 생산율은 $6.9{\pm}5.8{\mu}mol\;g^{-1}$ fresh weight(FW) $h^{-1}$, 질산염과 인산염 흡수율은 각각 $175.6{\pm}161.1\;nmol\;g^{-1}\;FW\;h^{-1}$, $12.7{\pm}10.1\;nmol\;g^{-1}\;FW\;h^{-1}$ 그리고 용존무기탄소 흡수율은 $8.9{\pm}7.9{\mu}mol\;g^{-1}\;FW\;h^{-1}$이었다. 다시마 엽장에 따른 이들 성분의 생산/흡수율은 로그함수 관계를 보여, 엽장 100~150 cm 이상부터는 다시마의 광합성 및 생장율이 다소 둔화되는 것으로 나타났다. 용존 산소 생산율과 질산염, 인산염, $TCO_2$ 흡수율은 각각 음의 선형관계를 보였으며, 특히 용존산소 생산율과 $TCO_2$ 흡수율은 높은 상관관계 ($r^2$=0.94)를 나타내어 서로에 대한 간접 지표가 될 수 있음을 의미한다. 다시마의 최대양지수율($F_v/F_m$)과 용존산소 및 무기탄소 생산/흡수율사이에 선형관계가 나타났으며, 양자수율이 높을수록 활발한 광합성작용으로 용존산소 생산이 활발함을 증명하였다. 광합성 형광특성 중 최대상대전자전달률은 비교적 엽체가 생장할수록 증가하였으며, 엽체의 부착부에 비해 상부 말단으로 갈수록 증가하였다. 이는 다시마가 생장할수록 광합성활성 조직 비(단위 면적당 습중량)가 증가하여 나타난 결과로 사료된다. 기장해역에서 다시마에 의한 연간 무기탄소 흡수량은 $1.0\sim1.7{\times}10^3C$ ton으로 추정되며, 이는 부산시 이산화탄소 배출량의 0.02~0.03%에 해당한다. 따라서 해조류에 의한 연안의 탄소 및 물질순환과 지구시스템에서의 역할을 파악하기 위해 추가적인 연구가 필요할 것으로 생각된다.

• 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.

• International Journal of Industrial Entomology and Biomaterials
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• 제8권1호
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• pp.73-76
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• 2004

The rate of oxygen consumption of the silkworm eggs was measured to set up the barometer for measuring the effect of egg chilling on diapause termination. In diapause eggs, $O_2$ uptake showed a maximum of 79.2 ${mu}ell$/mg eggs/hr, at one day after oviposition and then gradually decreased to 2.2${mu}ell$/mg eggs/hr at 9days. The rates of oxygen uptake of eggs raised immediately after HCl-treatment and reached to a maximal level of 484.5 ${mu}ell$/mg eggs/hr in 9-day-old eggs, which corresponds to 220 fold that of diapause eggs, and the hatching ability was also over 50％. In order to break diapause, eggs incubated at $25^{\circ}C$ for 30 days after oviposition had to be kept at least for 45 days at 5$^{\circ}C$, but chilled eggs for 90 days or longer hatched at 10 days as normal hatching periods. We also investigate periods which the value of $O_2$ uptake of eggs chilled during 15 to 120 days at 5$^{\circ}C$ reached at 200 ${mu}ell$/mg eggs/hr. As a result of that, $O_2$ uptake of eggs chilled during 15 to 45days were not reached at 200 ${mu}ell$/mg eggs/hr and longer the chilling durations are, the higher the rate of $O_2$ uptake is and the longer the chilling durations are, the shorter the periods up to hatching is. And also, hatch-ability increased rapidly as $O_2$ uptake reaches over 20/eggs/hr.

• 환경생물
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• 제32권4호
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• pp.297-305
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• 2014

부산시 강서구 낙동강 하구에서 채집한 방사무늬김(Porphyra yezoensis Ueda)의 용존산소 생산율은 $68.8{\pm}46.0{\mu}mol\;{g_{FW}}^{-1}h^{-1}$, 질산염과 인산염 흡수율은 각각 $2.5{\pm}1.8{\mu}mol\;{g_{FW}}^{-1}h^{-1}$, $0.18{\pm}0.11{\mu}mol\;{g_{FW}}^{-1}h^{-1}$ 그리고 용존무기탄소 흡수율은 $87.1{\pm}57.3{\mu}mol\;{g_{FW}}^{-1}h^{-1}$이었다. 용존산소 생산율과 질산염, 인산염, 용존무기탄소 흡수율은 각각 음의 선형관계를 보여, 광합성활동에 의한 결과물임을 파악할 수 있었다. 김의 생중량에 따른 이들 성분의 생산/흡수율은 로그함수적으로 감소하여, 성체(>~0.3 g)보다는 어린 엽체의 광합성효율이 매우 높은 것으로 나타났으며, 이는 질소부족으로 인한 황백화가 양식초기에도 발생할 수 있음을 제시하였다. 우리나라 시도 단위로 월별 생산되는 김 생산량과 양식면적을 바탕으로 질소요구량과 탄소흡수율을 산정한 결과, 생산량이 가장 높은 전라남도보다 부산(경상남도 포함)과 전라북도의 단위면적당 질소요구량이 높았다. 최근 김 황백화가 빈발하는 전라북도는 좁은 면적에서의 과밀 생산과 최대수확기가 육상과 저층으로부터 영양염 공급이 부족한 12~1월인 점 등이 황백화의 원인인 것으로 추정된다.

• ALGAE
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• 제32권2호
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• pp.139-153
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• 2017

The ability of a red tide species to take up nutrients is a critical factor affecting its red tide dynamics and species competition. Nutrient uptake by red tide species has been conventionally measured by incubating nutrient-depleted cells for a short period at 1 or 2 light intensities. This method may be applicable to certain conditions under which cells remain in oligotrophic water for a long time and high nutrients are suddenly introduced. Thus, a new method should be developed that can be applicable to the conditions under which cells are maintained in eutrophicated waters in healthy conditions and experience light and dark cycles and different light intensities during vertical migration. In this study, a new repletion method reflecting these conditions was developed. The nitrate uptake rates of the red tide dinoflagellate Prorocentrum micans originally maintained in nitrate repletion and depletion conditions as a function of nitrate concentration were measured. With increasing light intensity from 10 to $100{\mu}E\;m^{-2}s^{-1}$, the maximum nitrate uptake rate ($V_{max}$) of P. micans increased from 3.6 to $10.8 pM\;cell^{-1}d^{-1}$ and the half saturation constant ($K_{s-NO3}$) increased from 4.1 to $6.9{\mu}M$. At $20{\mu}E\;m^{-2}s^{-1}$, the $V_{max}$ and $K_{s-NO3}$ of P. micans originally maintained in a nitrate repletion condition were similar to those maintained in a nitrate depletion condition. Thus, differences in cells under nutrient repletion and depletion conditions may not affect $K_{s-NO3}$ and $V_{max}$. Moreover, different light intensities may cause differences in the nitrate uptake of migratory phototrophic dinoflagellates.

• Journal of Plant Biology
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• 제36권2호
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• pp.133-140
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• 1993

The photosynthetic activities in relation to oxygen evolution rates, quantum yield, CO2 uptake rates and room temperature chlorophyll fluorescence were investigated in cotyledons of cucumber seedlings exposed to low temperature (at 4$^{\circ}C$) for 24 h. Light-chilling caused more inhibition on light-saturated maximum oxygen evolution rates, quantum yield, and CO2 uptake rates than dark-chilling did in the cucumber plant. Light-chilling induced more marked increase in Fo and decrease in (Fv)m/Fm than dark-chilling did in the room temperature chlorophyll induction kinetics. The above results affected by chilling in the light are considered to be associated with the partial damage of the reaction center of PS II and the decreased photosynthetic activities. There occurred a large decrease in qQ with little change in qNP in the light-chilling plant. When light- and dark-chilled plants were recovered at room temperature for 24 h and their chlorophyll fluorescences were induced with light doubling technique, light-chilled plants showed more smaller magnitude and rate of fluorescence relaxation than dark-chilled plants. These suggest that light-chilling might cause some alterations in transthylakoid pH formation, and that photosynthetic apparatus of cucumber cotyledons is more susceptible to light-chilling. In the fast fluorescence induction kinetics, FR was decreased by 60% in the light-chilled plants with reference to $25^{\circ}C$ light-grown plants, while the dark-chilled plants showed a decreased rate of only 20% with reference to $25^{\circ}C$ dark-treated plants for 24 h, indicating that cucumber seedling is very sensitive to chilling stress. So, it is certain that chilling injury to the photosynthetic apparatus is strongly dependent on the presence of light in cucumber seedlings.

• 상하수도학회지
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• 제28권1호
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• pp.47-54
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• 2014

Nanotechnology has become one of the fastest developing technologies and recently applied to a variety of industries. Thus, increasing number of nano materials including various nanoparticles would be discharged into wastewater and consequently entering a biological wastewater treatment process. However, the impact of the nano particles on biological wastewater treatment has not been estimated intensively. In this research, we investigated the effect of silica nanoparticle on the oxygen uptake rates (OURs) of activated sludge used in a conventional wastewater treatment process. The inhibition (%) values were estimated from the results of OURs experiments for the silica nanoparticles with various sizes of 10-15, 45-50, and 70-100 nm and concentrations of 50, 250, and 500 ppm. As results, the inhibition value was increased as the size of silica nano particles decreased and the injected concentration increased. The maximum inhibition value was investigated as 37.4 % for the silica nanoparticles with the size of 45-50 nm and concentration of 50 ppm. Additionally, the effect of size and concentration on the inhibition should be considered cautiously in case that the aggregation of particles occurred seriously so that the size of individual particles was increased in aquatic solution.

• Journal of Oral Medicine and Pain
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• 제25권4호
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• pp.345-353
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• 2000

This study was to investigate normal salivary flow rates and normal indices of Quantitative analysis of salivary scintigraphy. 96 adult volunteers were studied by Questionnaire evaluating salivary conditions and clinical examinations. 35(male 23, female 12, age range 23-31years) that absented subjective and objective symptoms related saliva were classified as normal group. The normal group underwent measurement unstimulated and stimulated salivary flow rates and salivary scintigraphy. The obtained results were as follows: 1. There were not significant in sex differences of unstimulated and stimulated salivary flow rates. The unstimulated salivary flow rate was $0.66{\pm}0.41g/min$, stimulated salivary flow rates was $1.61{\pm}0.69g/min$. 2. As comparing of parameters of salivary scintigraphy, the Uptake ratio(UR), $T_{max}$, $T_{min}$, Maximum accumulation (MA), Maximum secretion(MS) of parotid and submandibular glands were not significant in sex and side-ralated differences. 3. The UR, $T_{max}$, MA, MS of parotid gland were significantly higher than those of submandibular gland; in the parotid gland, UR, $3.67{\pm}0.88$, $T_{max}$, $18.77{\pm}0.43min$, MA, $41.35{\pm}9.22%$, MS, $43.13{\pm}9.13%$; in the submandibular gland, UR, $3.04{\pm}0.10$, $T_{max}$, $18.48{\pm}0.52min$, MA, $36.47{\pm}14.18%$, MS, $36.88{\pm}12.20%$. 4. As classifying of time-activity curve, the most of parotid gland was N-type(97.1%), submandibular gland was observed in order of M-type(67.1%), N-type(21.4%), F-type(11.4%), however, was not observed S-type. 5. As the type of time-activity curve of submandibular gland was more flattened, the UR, $T_{max}$, MA, MS were significantly decresed.