• 펄프종이기술
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• 제36권4호
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• pp.77-82
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• 2004

Expression-deliquoring tests using three types of paper sludges (tissue, newsprint, and paperboard) as deliquoring agent were carried out in order to investigate the effects of sludge dosage and pressure on the expression-deliquoring of slurry. The addition of deli­quoring agent causes expression-deliquoring of slurry to be faster than would be the case without the deliquoring agent. In case of the tissue sludge, the highest compression rate was achieved when $5\%$ of deliquoring agent was added, while in cases of the news­print and the paperboard sludge, $7\%$. Compression rate was increased as pressure increases. Porosity was decreased as pressure increases. The lowest porosity was observed when $5\%$ of tissue sludge was added. When compared the weight of cake where deliquoring agent was not added and the weight of cake that was fastest expression-deliquoring, there was about $17.5\%$ of the weight reduction

• Journal of Ecology and Environment
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• 제30권2호
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• pp.109-119
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• 2007

The effect of water flow on the growth of Gafrarium tumidum was studied in the field using open cages constructed with stainless steel net and perspex in which holes were drilled. Cages with different flows (25, 50 and 75% of the control) were made by varying the area of perspex being drilled. Reduction in flow rate was directly proportional to the undrilled area, and the mean flow rate of the different treatment groups varied from 3.12 cm/s for the 25% exposure to 12.48 cm/s for the control cages. At the end of the 3-month experiment, no significant differences in sediment characteristics were found among the treatments. Growth in shell length, shell weight and tissue dry weight was, however, positively correlated with flow rate. Percentage increases ranged from $3.0{\sim}8.3%$ for shell length, $9.9{\sim}23.1%$ for shell weight and $17.2{\sim}53.3%$ for tissue dry weight. Condition index of the clam was not significantly different among the treatments. Seston depletion effect could reduce growth in G. tumidum only when water flow was reduced to 25% of the control. G. tumidum also exhibited different responses in shell and tissue growth at low flow rates, in which shell growth continued to decrease as flow rate decreased whereas tissue growth was relatively independent of low flows at 25 and 50% of the control. It was suggested that when seston flux was reduced at slow flows, it would be a better strategy for G. tumidum to channel energy for gonad development instead of shell growth during the reproductive stage.

• 한국발생생물학회지:발생과생식
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• 제25권1호
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• pp.67-72
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• 2021

This study investigated the IGF-1 signal in specific tissues using Pacific oysters artificially matured via water temperature elevation. Pacific oysters were subjected to water temperature elevation from March to June, and 20 were randomly sampled each month. The condition index (CI) and tissue weight rate (TWR) were examined by measuring shell length, shell height, shell width, and soft tissue weight. The IGF-1 signal in tissues (adductor muscle, digestive glands, gills, labial palps, mantle edges, and gonads) was analyzed by sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and Western blotting. From April to June, the TWR of females and males increased from 19.1±2.9 to 21.0±3.6 and 18.2±2.0 to 19.2±2.5, respectively, while the CI remained the same. The IGF-1 signal in each tissue differed. IGF-1 was expressed in the adductor muscle, while tyrosine was expressed in all tissues. The phosphor (p)-ERK and p-AKT activities were high in the adductor muscle, mantle edge, and gonads. IGF-1 signaling affected the growth and maturity of the Pacific oysters examined.

• ALGAE
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• 제25권1호
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• pp.17-26
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• 2010

The effects of salinity on various ecophysiological parameters of Ulva pertusa such as growth, nutrient uptake, photosynthetic performance and internal nutrient composition were tested. U. pertusa was collected from an eelgrass bed in a semi-protected embayment on the southwest coast of Korea. Under salinity regimes from 5 to 40 psu, the specific growth rates $(\mu)$ of U. pertusa ranged from 0.019 to $0.032\;d^{-1}$. Maximum growth rate was observed at 20 psu, and minimum at 40 psu. This species showed various uptake rates for nitrate and phosphate. Nutrient uptake was noticeably higher at intermediate salinity levels, and lower at both extremes. Salinity significantly influenced chlorophyll-$\alpha$ content and effective quantum yield. Tissue nitrogen content ranged from 1.5 to 2.9% N (dry weight), whereas tissue phosphorus ranged from 0.1 to 0.14% P (dry weight). The N : P ratio in the tissue of U. pertusa was considerably higher, ranging from 30 to 50. Increased growth at lower salinity suggests that the initial growth rate of U. pertusa is greater during the rainy season (i.e., late spring and early summer) than any other season during the year. The appearance of an Ulva bloom in eelgrass beds may be triggered by salinity more than by other environmental factors such as light and temperature.

• Journal of Ecology and Environment
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• 제30권2호
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• pp.127-133
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• 2007

The effects of water flow rate and phytoplankton concentration on the growth of the sandy shore clam Gafrarium tumidum was investigated in a laboratory flume study using a $3{\times}3$ factorial design. After 60 days, shell length, shell weight and tissue dry weight increased significantly with phytoplankton concentration. For the effect of flow rate, growth was faster when flow rate increased from low to medium level; further increases in flow rate, however, either did not sustain faster growth or resulted in a reduction in growth. The condition index (CI) of a standard-sized clam was significantly higher at low flow rate than at medium and high flow rates and was negatively correlated with phytoplankton concentration. The uncoupled growth of shell and tissue in response to flow rate and phytoplankton concentration may be adaptations to low food environments, so that energy can either be stored to sustain life or reserved for gametogenesis during the reproductive period.

• 한국식품영양학회지
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• 제19권4호
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• pp.358-365
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• 2006

두께 1 mm의 감자 절편을 분자량 200에서 6000까지의 PEG용액에 침지했을 때 PEG의 분자량이 작을 수록 초기 탈수 속도가 빨랐으나 최종 탈수량은 PEG 분자량이 클수록 증가하여 PEG 6000인 경우 초기수분의 약 80%까지 탈수되었다. 감자절편을 저분자 용액인 NaCl, PEG400 용액에 침지한 경우, 조직의 뒤틀림 현상은 나타나지 않고 plasmolysis가 일어나면서 탈수와 부피가 감소되는 반면, PEG 600 용액에 침지시부터 조직의 뒤틀림 현상이 동반된 탈수 현상이 나타났으며, 고분자 용액인 PEG 4000 용액에 침지한 경우 cytonhysis 현상을 동반한 탈수와 부피 감소가 더욱 분명하게 관찰되었다. 초기 탈수 속도는 저분자 용액에 침지 시 더 빨랐으나 최종 탈수량은 고분자용액에 침지 시 더 컸으며 탈수량이 역전되는 시기는 cytorrhysis가 일어나는 시기와 일치하였다. 따라서 고분자 용질의 고농도 용액에 시료를 침지하면 용질의 함침량은 적게 하면서 탈수량을 증가시킬 수 있음을 알 수 있었다.

• 원예과학기술지
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• 제28권3호
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• pp.363-369
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• 2010

조직배양구를 순화시키기 위하여 상토에 정식을 할 때 순화율을 높이고 구 비대에 적합한 재식밀도와 깊이를 구명하고자 시험을 수행되었다. 오리엔탈나리 대표 품종들인 '시베리아'와 '솔본느' 조직배양구의 효과적인 순화를 위한 재식 밀도를 200, 400, 600, 800, 1,000구/$m^2$ 단위로 하였으며, 재식깊이 시험을 위해 상토의 복토를 1, 3, 6, 9, 12cm로 나누어 정식하였다. 오리엔탈나리 '시베리아'의 경우 $m^2$ 당 400구 재식시 생존율 87.3%, 구주 6.4cm, 구중 8.3g, 구주 6cm 이상 비율 61.6%로 가장 적합하였다. '솔본느'의 경우도 400구/$m^2$에서 생존율 88.8%, 구주 5.0cm, 구중 7.1g 으로 가장 효율적인 것으로 생각되었다. 오리엔탈나리 '시베리아'와 '솔본느' 조직배양구의 순화를 위한 적정 재식깊이는 '시베리아'의 경우 지표면에서 3cm 재식구가 생존율 77.8%, 구주 5.9cm, 구중 7.9g, 구주 6cm이상 비율 47.2-51.0%로 가장 양호하였고, '솔본느'의 경우도 3cm 재식구에서 생존율 87.1%, 구주 5.1cm, 구중 6.5g로 가장 양호하였다.

• Asian-Australasian Journal of Animal Sciences
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• 제14권11호
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• pp.1560-1563
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• 2001

An ability to utilize the substrates (acetate, glucose and lactate) in the lipid synthesis was measured in vitro with the adipose tissues of 4 locations (subcutaneous, SUBC; intramuscular, INTR; tail and kidney, KIDN) in 12 Hanwoo (Korean native cattle) steers (26 and 28 months of ages, mean body weight 638.6 kg). The rates of lipid synthesis from acetate were higher than those from glucose in SUBC and ITRA adipose tissues, respectively. In contrast, the rates of lipid synthesis from glucose were higher than those from acetate in the adipose tissues of tail and KIDN, respectively. Lactate utilization was lowest in all the locations while that of acetate or glucose had the different trends of utilization in the lipogenesis. The rate of lipid synthesis from acetate was highest in the SUBC adipose tissue but was lowest in the KIDN while that from glucose was also higher in the SUBC adipose tissue than in the other tissue locations. The rate of lipid synthesis from lactate, however, was highest in the tail adipose tissue among the locations.

• 한국작물학회지
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• 제38권2호
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• pp.159-165
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• 1993

대두에서 각각 50%의 협제거와 협제거 처리에 의해서 변화된 동화물질에 대한 sink demand가 엽의 광합성율과 각 부위별 단백질 함량 및 엽의 노화에 미치는 영향을 구명하기 위하여, 1990년 고려대학교 자연자원대학, 식량자원학과 실험포장에서, pot에 팔달콩을 공 시하여 총건물중과 엽을 제외한 vegetative tissues의 건물중, 잎과 뿌리의 전분함량, 엽의 광합성율과 기공저항성, 각 부위별 단백질함량, 엽의 chlorophyll content등을 조사한 결과를 요약하면 다음과 같다. 1. 엽을 제외한 vegetative tissues의 건물중은 협제거 처리에 의해서 증가되었고, 따라서 협제거 처리에 의한 총건물중의 감소는 유의성이 없었다. 2. 종실의 100립종은 대조구와 비교할 때, 50% 협제거 처리에 의해 6.4% 증가하였으며, 50% 엽제거 처리에 의해서 3.0% 감소하였다. 3. 엽의 전분함량은 처리 후 22일부터 감소되었고 뿌리의 전분함량은 전 시기에 걸쳐 감소되었는데, 잎과 뿌리의 전분함량은 협제거 처리에 의해 높아지고 엽제거 처리에 의해 낮아지는 경향을 보였다. 4. Specific leaf weight는 협제거 처리에 의해 증가되었고 엽제거에 의해 감소 되었다. 5. 엽의 광합성율은 전 시기에 걸쳐서 높아졌으며, 협제거 처리에 의해 증가되었다. 7. 잎, 중기+엽병, 뿌리 등의 단백질함량은 점차로 감소되는 경향이었으며, 협제거 처리에 의해 높아졌고 엽제거에 의해 낮아지는 경향을 보였다. 8. 성숙기( $R_{7}$)의 종실의 단백질함량은 협제거와 엽제거 처리에 의해 유의성 있는 차이를 나타내지 않았다. 9. 엽의 chlorophyll content의 감소에 의한 엽의 외관상 노화는 협제거처리에 의해 지연되었고 엽제거에 의해 촉진되었다. 10. 광합성율의 감소에 의한 엽의 기능상 노화는 엽제거 처리에 의해 촉진되었다.

• 생물환경조절학회지
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• 제15권4호
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• pp.369-376
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• 2006

코이어(CO), 피트모스(PM) 또는 코이어+피트모스 (5:5, v/v, COPM)에 펄라이트(PL)를 0, 20또는 40% (v/v) 혼합하여 9종류의 상토를 조제하고, 고추 '녹광'을 플러그 육묘하면서 작물 생육 및 무기원소 흡수에 미치는 영향을 구명하기 위하여 본 연구를 수행하였다. 연구 목적을 달성하기 위하여 72공 플러그 트레이에 파종하고 플러그 육묘하면서 파종 35일 및 70일 후에 지상부를 채취하여 식물 생육 및 무기원소 함량을 조사 및 분석하였다. CO는 PL의 혼합비율이 증가할수록 생체중 및 건물중 생산량이 많았으나, PM은 PL를 20% 혼합한 처리에서, 그리고 COPM는 PL 0% 처리에서 파종 35일 후 생체중과 건물중이 가장 무거웠다. 파종 70일 후의 생육도 35일 후의 결과와 유사였다. CO와 PM은 PL의 혼합 비율이 높아질수록 파종 3일 후의 식물체내 $P_2O_5$과 K 함량이 감소하고, Ca 및 Mg 함량이 증가하였다. CO 혼합 상토가 동일한 PL 비율의 PM 또는 COPM 상토보다 Ca 및 Mg 함량은 낮았으나, K 함량은 월등히 높았다. 파종 70일 후 CO 또는 PM에 PL의 혼합비율이 증가할수록 $P_2O_5$와 K 함량이 감소하였다. 식물체의 Ca및 Mg는 CO의 경우 20% PL, PM은 40% PL, 그리고 COPM은 40% PL 처리에서 각 유기물내의 다른 PL 처리보다 함량이 많았다.