• 한국수산과학회지
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• 제50권2호
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• pp.175-182
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• 2017

We examined the effects of environmental factors on zoospore release and germling growth of the green tide alga Cladophora albida under various conditions of temperature${\times}$irradiance (zoospore release), temperature${\times}$irradiance${\times}$ nutrient (germling growth), and a single factor test of salinity. Zoospore release was maximized at $30^{\circ}C$ and $100{\mu}mol\;photons\;m^{-2}s^{-1}$ in the temperature irradiance experiment and at 34 psu in the salinity experiment. Maximum germling growth was observed at $25^{\circ}C$ with $100{\mu}mol\;photons\;m^{-2}s^{-1}$ and PES (Provasoli's Enriched Seawater) in the temperature irradiance nutrient experiment, and at 34 psu in the salinity experiment. Germlings grew faster at higher irradiances for a given temperature level, and also grew faster as salinity increased over the range of 5-34 psu. Overall, optimal environmental conditions for zoospore release were $30^{\circ}C$, $100{\mu}mol\;photons\;m^{-2}s^{-1}$ and 34 psu. Maximal germling growth occurred at $25^{\circ}C$, $100{\mu}mol\;photons\;m^{-2}s^{-1}$, PES, and 34 psu. C. albida blooms are most likely to occur under these optimal environmental conditions, as plentiful zoospore release and rapid germling growth lead to population growth.

• Bulletin of the Korean Chemical Society
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• 제35권5호
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• pp.1333-1336
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• 2014

Expanded polytetrafluoroethylene (ePTFE) grafts have been used as vascular access for many patients suffering from end stage renal disease. However, the vascular graft can cause significant clinical problems such as stenosis or thrombosis. For this reason, many studies have been performed to make drug eluting graft, but initial burst is major problem in almost drug eluting systems. Therefore we used biodegradable polymer to reduce initial burst and make sustained drug delivery. The ePTFE grafts were dipped into a paclitaxel-dissolved solution and then PLGA-dissolved solution was passed through the lumen of ePTFE. We analyzed whether the dose of paclitaxel is enough and the loading amount of PLGA on ePTFE graft increases according to the coating solution's concentration. Scanning electron microscope (SEM) images of various concentration of PLGA showed that the porous surface of graft was more packed with PLGA by tetrahydrofuran solution dissolved PLGA. In addition, in vitro release profiles of Ptx-PLGA graft demonstrated that early burst was gradually decreased as increasing the concentration of PLGA. These results suggest that PLGA coating of Ptx loaded graft can retard drug release, it is useful tool to control drug release of medical devices.

• 한국안전학회지
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• 제29권1호
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• pp.21-24
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• 2014

In this study, we have investigated the maximum smoke density and the initial stage smoke density in order to see the characteristics of smoke release of the architectural surface materials and the architectural adhesives, using smoke density chamber. As a result of the study, polyurethane foam showed the highest smoke density index, 206.55 within 10 min. In the case of the other samples, reinforced styrofoam was followed as 39.90, general styrofoam 33.73, and glass fiber 5.40, respectively. In the intial stage of a fire, it is forecasted actually to give hardship at the clear visibility. In the case of architectural adhesives, the highest ranking was those for windows and doors 509.64, stone 275.63, wood 232.25, tile 18.65, and styrofoam 6.44 were followed, respectively. This result is an early research to show characteristics of smoke release through experiment. However, it is meaningful that this study can be used as a basic for further study on architectural fire hazard prediction.

• The Korean Journal of Physiology and Pharmacology
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• 제8권2호
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• pp.69-76
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• 2004

A variety of G protein coupled receptors (GPCRs) are expressed in the presynaptic terminals of central and peripheral synapses and play regulatory roles in transmitter release. The patch-clamp whole-cell recording technique, applied to the calyx of Held presynaptic terminal in brainstem slices of rodents, has made it possible to directly examine intracellular mechanisms underlying the GPCR-mediated presynaptic inhibition. At the calyx of Held, bath-application of agonists for GPCRs such as $GABA_B$ receptors, group III metabotropic glutamate receptors (mGluRs), adenosine $A_1$ receptors, or adrenaline ${\alpha}2$ receptors, attenuate evoked transmitter release via inhibiting voltage-activated $Ca^{2+}$ currents without affecting voltage-activated $K^+$ currents or inwardly rectifying $K^+$ currents. Furthermore, inhibition of voltage-activated $Ca^{2+}$ currents fully explains the magnitude of GPCR-mediated presynaptic inhibition, indicating no essential involvement of exocytotic mechanisms in the downstream of $Ca^{2+}$ influx. Direct loadings of G protein ${\beta}{\gamma}$ subunit $(G{\beta}{\gamma})$ into the calyceal terminal mimic and occlude the inhibitory effect of a GPCR agonist on presynaptic $Ca^{2+}$ currents $(Ip_{Ca})$, suggesting that $G{\beta}{\gamma}$ mediates presynaptic inhibition by GPCRs. Among presynaptic GPCRs glutamate and adenosine autoreceptors play regulatory roles in transmitter release during early postnatal period when the release probability (p) is high, but these functions are lost concomitantly with a decrease in p during postnatal development.

• Clinical and Experimental Reproductive Medicine
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• 제7권1_2호
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• pp.3-10
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• 1980

뇌하수체의 성선자극 홀몬 분비 세포는 혈액내 estradiol양의 변화에 따라 LH와 FSH를 분비하므로써 주기적인 변화를 보인다. 성선 자극 홀몬의 분비는 성선 자극 홀몬을 합성하고 보유하는 두가지 형태의 능력의 크기에 의하여 조절되며 이들을 조절하는 것은 시상하부에서 분비되는 황체형성 홀몬-분비 홀몬(LH-RH)과 난소에서 분비되는 estradiol이다. LH-RH는 성선 자극 홀몬 분비세포에 작용하여 성선 자극 홀몬 합성, 저장 및 분비를 촉진시키며 estradiol은 LH-RH의 기능을 확대하고 LH-RH가 self-priming효과를 나타내도록 유도하기도 하며 LH-RH의 성선 자극 홀몬 분비 기능을 저해하기도 한다. Estradiol은 기저성 성선 자극 홀몬을 분비시키기 위하여 negative feedback작용을 하고 배란성 성선 자극 홀몬을 분비시키기 위하여는 positive feedback작용을 하며 feedback작용 부위는 시상하부 및 뇌하수체 전엽이다. 또한, estradiol이 feedback작용을 하여 성선 자극 홀몬의 분비를 조절하는 데는 LH-RH뿐만 아니라 중추신경-시상하부에서 분비되는 dopamine, norepinephrine, prostaglandin등이 참여한다.

• 융복합기술연구소 논문집
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• 제9권1호
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• pp.13-19
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• 2019

The purpose of this study is to suggest a new method to determine a combustion phase (start of combustion and end of combustion) using a combustion pressure data. Unlike previous research method that used heat release amount, the difference between the combustion pressure measured in the combustion chamber and the motoring pressure was used to determine the combustion phase. This research was conducted using a single-cylinder diesel engine with a compression ratio of 17.7. The test was conducted under various injection timing. The newly proposed method showed high accuracy in combustion mode with early injection, as well as the conventional combustion mode. It is expected that this method will be used to study new combustion strategies such as HCCI (homogeneous charge compression ignition) and RCCI (reactivity controlled compression ignition) that are applying early injection strategies as well as existing combustion modes.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2004년도 하계학술대회 논문집 D
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• pp.2468-2470
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• 2004

In the field of construction work, a shackle is one of the most essential tools to build up a structure on the foundation. The old-style process, 3 construction crew climbs up the beam to release it from the shackle, is hazardous and very inefficient. For this reason, the auto shackle controller with two shackles, which can release the beam through a wire-less command, was developed. The auto-shackle controller makes the work safer and more efficient. However, the early auto-shackle controller itself was heavy and had some sorts of problems in safety and durability. Recently, the high efficient battery was developed. It makes develope a super miniaturized high performance auto shackle controller. In this paper, we analyze problems of early auto shackles and present the latest result of a super miniaturized auto-shackle controller.

• Weed & Turfgrass Science
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• 제4권4호
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• pp.383-389
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• 2015

The use of zoysiagrass (Zoysia japonica Steud.) in the transition zone is limited because of a lack of cold hardiness although zoysiagrass has many advantages compared to other warm-season and cool-season grasses. Late-fall N fertilization is often applied for darker green color of turfgrass in early spring and more extensive root growth without rapid top growth. The objective of the study was to evaluate the effects of late fall N application and turf cover for zoysiagrass spring green-up. Clear polyvinyl chloride (PVC) film was used for turf cover. The amount of N applied were 5 and $10g\;N\;m^{-2}$ for the low and high N rate treatments, respectively. Covered zoysiagrass had greater turfgrass color and quality in early spring than non-covered zoysiagrass. The high N rate had 0.6 to 2.3 greater turfgrass quality than the low N rate on 7 of 9 rating dates. Slow-release N as late fall fertilization is more effective for turfgrass color and quality than fast-release N in spring. Turf cover could reduce the period of yellow zoysiagrass, and the earlier time of spring green-up could be advanced by increasing turfgrass quality and growth of zoysiagrass.

• 식물병연구
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• 제10권4호
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• pp.209-216
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• 2004

The circular leaf spot of persimmon is occurred almost every place where persimmon is cultivated, especially the disease outbreak severely in southern part of Korea. The disease reveals unusually long incubation period after pathogen invade into leaf tissue and no practical control measure is available once the symptom has appeared. Most of the farmers just follow the suggested spray schedules calculated on the basis of weather condition of ordinary years. Therefore the damages due to circular leaf spot greatly differ year after year. In this article, we tried to describe and summarized the investigation on the circular leaf spot pathogen, Mycosphaerella nawae, related to disease outbreak such as overwintering of pathogen, inoculum formation and spread, incubation period after infection, and secondary inoculum. With the summary of these results, we suggest the disease cycle of circular leaf spot of persimmon. The pathogen overwinters in diseased leaves as mycelial form or pseudoperithecial premodium. The pseudoperitheria become matured in spring as the temperature raise and forms asci and ascospores. The maturation of pseudoperithecia are closely related to the temperatures during March and early April. The ascospores completely mature in early May and the ascospores released when the pseudoperithecia absorbed enough moisture after rainfall. The release of ascospores are diverse greatly with the variation of maturity of pseudoperithecia. Generally the spore start to release from middle of May to early of July. Duration of ascospore release is depend on the weather condition of particular year, especially amount and number of precipitation. The ascospores produced from pseudoperithecia is known to the only inoculum for circular leaf spot disease. But according to the results obtained from our investigations, the conidia formed on the lesions which incited by natural infection. This conidia are infectious to persimmon leaves and formed identical symptom as natural infection. The time of producing secondary inoculum of circular leaf spot of persimmon is considered too late to develop new disease. Generally the importance of secondary inoculum is low but the conidia produced in early September are competent to develop new disease and new infection also significantly affect to harvest of persimmon. The importance of circular leaf spot disease is recognized well to farmers. The approaches to control of the disease should be initiated on the basis of the knowledges of inoculum dynamics and ecology of disease development. The forecasting system for circular leaf spot is need to be developed.

• 아시안잔디학회지
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• 제22권1호
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• pp.65-74
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• 2008

본 연구는 우리나라 늦가을부터 초겨울의 집중적인 답압피해를 줄이기 위해 답압 시간과 비료의 종류가 골프장 그린에 식재된 크리핑 벤트그래스의 생육과 품질에 미치는 영향을 구명하고자 하였다. 실험기간은 2005년 10월 1일$\sim$2005년 11월 30일까지 약 2개월간 인천그랜드 골프장내 시험포장에서 크리핑 벤트그래스의 '씨 사이드 II' 품종을 대상 실시되었고 실험구의 크기는 1m $\times$ 1.5m이며 3반복 완전임의배치법으로 하였다. 시험구 처리는 대조구와 답압 시간대(오전, 정오, 저녁) 및 비료종류(속효성 비료 1종, 완효성 비료 4종)를 달리한 실험을 수행하였다). 조사항목은 엽색, 질감, 밀도 및 내답압성을 시각적으로 평가하였고 잔디 밀도(개/$cm^2$), 뿌리길이(cm)를 조사하였다. 그 결과를 요약하면 다음과 같다. 1. 답압 시간대 변화에 따른 잔디 엽색 및 잔디질감은 답압처리 20일 이후인 10월 중순부터는 낮 1시부터 2시 사이 처리한 대조구 A4(10-15-10+정오)에 비해 오전 6시부터 7시 사이 처리한 A16(10-15-10+아침)에서 잔디품질이 나빠졌다. 잔디품질과 내답압성은 아침 시간대인 처리구(A16)와 저녁시간대 처리구(A17)는 낮 시간대 A4와 비교하여 큰 차이는 없었으나 11월 이후 일교차가 커지면서 품질이 떨어졌다. 2. 답압 시간대 변화에 따른 잔디 분얼경 밀도는 답압 30일후의 측정에서 대조구인 A4에 비해 A16가 밀도가 크게 떨어졌다. 또한 뿌리길이는 지상부 평가와는 달리 큰 차이가 없었다. 즉 단기적으로는 아침시간대의 답압이 지하부보다는 지상부 생육에 미치는 것으로 나타났다. 3. 비료 종류의 변화에 따른 잔디 엽색은 처리 후 10일까지는 속효성 비료인 A18의 엽색이 진하였다. 그러나 실험 기간이 지나면서 질소성분이 지속적으로 공급되는 완효성비료 처리구인 A20(11-3-22), A21(20-3-20) 및 A22(10-3-10)가 진한 엽색을 유지하였다. 잔디의 질감은 잔디의 엽색과 달리 실험 30일 이후 A4와 Al8가 낮았다. 잔디품질과 내답압성은 속효성 비료인 A18보다 완효성 비료 처리구(A22)가 가장 좋았다. 4. 잔디 분얼경 밀도는 실험 15일과 30일 후 각각 20.2개/$cm^2$와 16.3개/$cm^2$로 A22가 가장 많았다. 그러나 처리구별 평균 잔디 분얼경밀도는 답압처리 15일 이후부터 답압 전 26개에서 20.2개, 13.6개로 급속히 감소하였다. 뿌리길이는 A18가 11.7cm로 가장 짧았고 다른 처리구에서는 14$\sim$14.3cm로 차이 적었다. 이상 결과를 종합하여 보면 잔디의 답압으로 인한 피해를 최소화하고 건강한 잔디생육을 위하여 첫째, 관리적 방법으로 답압피해가 심할 수 있는 아침이나 저녁시간대의 관리작업 및 내장객 답압을 최소화하기 위해 홀컵 이동이나 교체시기를 탄력적으로 운영해야 할 것이다. 둘째, 동계기간 중에는 티업시간을 최대한 늦추거나 마지막 티업 시간을 당겨서 이른 아침과 저녁시간에 서리와 잔디의 결빙으로 인한 잔디의 손상을 최소화하여야 할 것이다. 셋째, 비료의 선택에 있어 단기적으로 답압과 마모가 예상되는 경우에는 왕성한 회복을 촉진하는 속효성 비료를 선택한다. 반면 시간의 경과에 따른 생육의 균일도, 즉 엽색이나 밀도 등을 가능한 오랜 기간 동안 일정하게 유지할 경우 완효성 비료를 사용해야 할 것으로 판단된다.