• Journal of Bio-Environment Control
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• v.24 no.3
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• pp.264-270
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• 2015

Tropical night phenomenon has been increasing due to global warming recently, it is expected that fruit quality of apples will decrease due to elevated night temperature condition. In the present study, fruit quality at maturity, periodic anthocyanin biosynthetic gene expression and sugar contents in leaves and fruit flesh were investigated to establish the physiological responses of 'Fuji' apples under high night temperature. The night temperature were treated with such as ambient (control), ambient $-4^{\circ}C$, and ambient $+4^{\circ}C$. After the treatment, high night temperature didn't affect fruit diameter, weight, and soluble sugar contents. Coloration of ambient $+4^{\circ}C$ was poor than that of control, however there was no significant difference between these genes expression of control and that of ambient $+4^{\circ}C$ treatment in the late coloration season. Increase of sorbitol and glucose contents at ambient $+4^{\circ}C$ in leaves were smaller than those at control, and then sorbitol and sucrose contents in fruit flesh at ambient $+4^{\circ}C$ were smaller than those at control. The cross section of leaves showed that there were no differences with the structure of parenchyma and epidermis tissues between the treatments, but starch granules in the palisade parenchyma cells decreased in high night temperature treatments. Consequently, high night temperature didn't affect the fruit quality, but changed sugar contents in leaves and fruit flesh, and suppressed coloration regardless of anthocyanin biosynthetic gene expression.

• Korean Journal of Agricultural and Forest Meteorology
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• v.17 no.1
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• pp.75-84
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• 2015

This study was conducted to investigate the effects of high temperature and drought on growth performance, photosynthetic parameters and photosynthetic pigment contents of Liriodendron tulipifera L. seedlings. The seedlings were grown in controlled-environment growth chambers with combinations of four temperature ($-3^{\circ}C$, $0^{\circ}C$, $+3^{\circ}C$, $+6^{\circ}C$; based on the monthly average for 30 years in Korea) and two water status (control, drought). Temperature rise increased growth, total dry weight and leaf area in all water status. Also photosynthetic rate, dark respiration, stomatal conductance and transpiration rate increased with increasing temperature. In contrast, growth and photosynthetic parameters of L. tulipifera seedlings were lower in $-3^{\circ}C$ than $0^{\circ}C$. But temperature rise decreased water use efficiency in all water status. Temperature rise increased photosynthetic pigment contents of leaf. Also chlorophyll a/b ratio increased with increasing temperature. In conclusion, the elevated temperature lead to causes growth increase through the increase of energy production by higher photosynthetic rate during a growth period of L. tulipifera seedlings.

• Proceedings of the KSEEG Conference
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• 2003.04a
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• pp.258-264
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• 2003

중력이상 및 수치고도모델을 이용하여 한반도 모호면 심도를 추출하였다 중력이상값은 인공위성고도레이더 관폭값을 주로 이용한 전지구 모델을 이용하여 데이터영역 뿐 만 아니라 주파수영역에서도 자료의 균질성을 확보하였다. 모호면 추출은 Kim et al. [2000a]에 의해 제안된 스펙트럼 대비법 및 후리에급수를 이용한 파워스펙트럼분석법을 이용하였다. 전자는 지각근형을 전제로, 지형에 의한 중력효과와 후리에어 중력이상을 파동수영역에서 대비하여 모호면의 심도를 계산하는 방법이고, 후자는 완전부우게 중력이상으로부터 푸리에변환을 이용하여 지하 밀도 변화층의 심도를 계산하는 방법이다. 이 두 모호면은 서로 0.53의 상관관계를 갖고 있으며, 이는 모호면 산출의 방법론적인 차이 및 계산상의 오차인 것으로 사료된다. 이렇게 두 가지 독립적인 방법으로 추출된 모호면을 하나로 통합하기 위한 한 방법으로, 두 모호면의 차이를 계산한 후, 이를 최소자승법을 이용, 두 모호면을 보정하였다. 결과적으로 한반도의 최종 모호면의 평균심도는 32.0km, 표준편차는 2.5km 이며, 최소, 최대 심도는 20.3, 36.6km으로 나타났다. 이 경우 지형에 의한 중력효과는 스펙트럼대비법에 의해 제거된 결과이나, 한반도의 지각이 완전한 지각판 내에 놓여 있어서 Airy-Heiskanin 지각균형설의 가정이 타당성이 있는가, 혹은 국부적인 응력장에 의해 한반도의 지각이 과연 얼마나 지지되고 있는가 하는 것에 대한 추가적인 연구가 필요하며, 이에 앞서, 일정한 밀도차를 갖는 연속적인 밀도변화층이 존재한다는 가정이 반드시 필요하다.에는 관련성을 갖고 있으며, 이는 유류 분해정도를 파악하는 지시자로써 특정 무기 오염물질을 이용할 수 있을 가능성이 있으므로 좀더 이들 관계성에 대한 연구가 진행될 필요성이 있다고 판단된다.고 과학적으로 분석할 수 있는 방법이 될 수 있을 것으로 기대된다. 의미를 되새기는 것으로 짧은 연구를 시작하겠다. 등은 활성 값이 70% 이상으로 퇴적물 독성이 상대적으로 낮았다. 이중나선 DNA 함량은 28.4 % - 49%로 대조군에 비해서 감소가 크다. 대부분의 정점이 대조군의 30% 내외로 정점 간의 차이는 크지는 않다. 그러나 다른 측정자료와 같이 정점 22에서 18%로 최소치를 나타내고, 정점 2, 12에서 20% 내외의 값을 보인다. 종합적으로 볼 때 오염물질의 유입이 크고, 광양제철 인근 정점 들이 모두 다른 정점에 비해서 낮아서, 퇴적물 독성이 높은 정점으로 조사되었다.hiwo의 광합성 능력은 낮은 농도들에서는 대조구와 유사하였으나, 5 $\mu\textrm{g}$/l의 높은 농도에서는 초기에 매우 낮은 광합성 능력을 보이다가 시간이 경과하면서 대조군보다 더 높은 경향을 나타냈다. 이러한 결과는 식물플랑크톤이 benso[a]pyrene의 낮은 농도에서 노출될 때는 이 물질을 탄소원으로 사용할 가능성이 있음을 시사한다. 본 연구의 결과들은 연안해역에 benso[a]pyrene과 같은 지속성 유기오염물질이 유입되었을 때 내정여부에 따라 식물플랑크톤 군집내 종 천이와 일차생산력에 크게 영향을 미칠 수 있음을 시사한다.TEX>5.2개)였으며, 등급별 회수율은 각각 GI(8.5%), GII

• Journal of Wetlands Research
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• v.15 no.3
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• pp.289-300
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• 2013

In this study, two types of wetland plants, Eichhornia crassipes (a floating plant) and Ceratophyllum demersum (a submerged plant) were introduced to wetland mesocosms to understand how the water properties of wetlands such as pH, dissolved oxygen content, water temperature, oxidation reduction potential, and nutrient concentrations are affected by different types of wetland plant. The floating plant lives on the water surface and can block light penetration; it exhibited the lowest water temperature and temperature difference between lower and upper layers. After the addition of contaminants, the dissolved oxygen (DO) concentration decreased abruptly but recovered continuously in all mesocosms; especially the submerged plants, which photosynthesize in water, showed the largest increases in DO and diel periodicity DO, as well as in pH value. The oxidation-reduction potential in both water and sediment were affected by the presence of wetland plants and plant type and the results suggest that various aspects of wetland biogeochemistry are affected by the presence and type of wetland plants. The total nitrogen and phosphorous concentrations in water decreased in the following order: Water only < Water + Soil < Floating Plants < Submerged Plants. Although both floating and submerged plants can control algal concentrations, the effect was more prominent for floating plants.

• Journal of Korean Society of Forest Science
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• v.89 no.4
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• pp.513-521
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• 2000

Red alder (Alnus rubra Bong.) seedlings inoculated with Frankia pure cultures were grown in a walk-in growth chamber for sixteen weeks. Half were inoculated with the spores of the ectomycorrhizal fungus Alpova diplophloeus (Zeller & Dodge) Trappe & Smith. The mycorrhizal seedlings were significantly larger than nonmycorrhizal plants in diameter, and nodule and shoot dry weight by 6 to 16% when their heights were very similar. The mycorrhizal effects on water relations of red alder seedlings were explored in a 30 hours water stress. Mycorrhizal and nonmycorrhizal seedlings did not significantly differ in leaf water potentials, $CO_2$ exchange rates or $N_2$-fixation rates during the drought. Our results suggests that A. diplophloeus mycorrhizas increased red alder seedling growth under well-watered conditions but do not affect water relations of the plant under water-stress.

• Journal of Wetlands Research
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• v.13 no.3
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• pp.471-479
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• 2011

Evapotranspiration (ET) including evaporation from a land surface and transpiration from photosynthesis of vegetation is a hydrological factor that has an important role in water cycle. However, there is a limitation to understand it due to heterogeneity of land cover and vegetation. In this study, Mapping EvapoTRanspiration with Internalized Calibration (METRIC) model, one of the energy balance models, and MODerate resolution Imaging Spectroradiometer (MODIS) satellite based well-known Penman-Monteith algorithm were compared. Two ET maps were categorized and compared by land cover classification. The results represented overall applicability of the two models with the highest correlation coefficients in needleleaf and broadleaf forests. This study will be useful to estimate remote sensing based ET maps with high resolution and to figure out spatio-temporal variability and seasonal changes.

• Korean Journal of Microbiology
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• v.40 no.2
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• pp.115-120
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• 2004

A Gram (-), rod-shaped bacterium in size of 1.3∼$1.8{\times}0.35{\mu}m$ inhibiting the growth of cyanobacterium (Ana-baena cylindrica) was isolated and designated NG-2 in this manuscript. This isolate showed positive reactions for catalase and oxidase, and optimal growth conditions of 35∼TEX>$40<^{\circ}C$ and pH 9.0. In a mixed-culture of A. cylindrica and the isolate, each microorganism grew inverse-proportionally, and the cyanobacterial vegetative cells almost completely disappeared within 24 hours. NG-2 lysed A. cylindrica only under light, which means that lytic activity of NG-2 was dependent on the photosynthetic activity of host. When observed under phase contrast microscope, the isolate lysed vegetative cells of A. cylindrica in scattered state in a liquid medium, whereas het-erocysts have not been lysed. When cyanobacterial cell walls have been lysed partly, NG-2 attatched around A. cylindrica filament and formed colony, then encouraged complete lysis of cyanobacterial cells. The isolate showed similar lytic activity in natural water as in an artificial medium. And lytic activity of NG-2 was enhanced when attached on expandable polystyrene bead.

• Journal of Biosystems Engineering
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• v.26 no.4
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• pp.379-384
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• 2001

To enhance the smooth graft-taking of grafted seedlings, the excessive evapotranspiration from grafted seedlings just after grafting should be avoided. A measurement system of the evapotranspiration rate of grafted seedling under artificial lighting was set up to investigate the effect of physical environment on the evapotranspiration and graft-taking characteristics of grafted seedlings quantitatively. The evapotranspiration rate of grafted seedlings affected by relative humidity and light intensity were analyzed using the measurement system. The hypocotyl of watermelons (Citrullus vulgaris cv. Sweetdew, Hungnong Seed Co.) was slantly cut and then inserted into a hole on the stem of rootstock (Lagenaria siceraria cv. FR-King, Hungnong Seed Co.). Grafted seedlings were healed and joined for 5 days under cool-white fluorescent lamps (FL20SEX-d/18, Keumho Electric Co.) with photoperiod of 12h$.$d$\^$-1/ except dark period for one day after grafting in a closed graft-taking enhancement system developed by Kim(2000). The evapotranspiration rate and graft-taking of grafted seedling at air temperature of 23$\^{C}$ and air current speed of 0.1m$.$s$\^$-1/ was highly affected by relative humidity. But light intensity showed higher effect on the stem length of scion than relative humidity. In conclusion, it was suggested that relative humidity should be controlled at higher than 90% with photosynthetic photon flux of 50$\mu$mol$.$m$^2$$.$s$\^$-1/ to increase the survival of grafted seedlings and to produce healthy seedlings.

• Korean Journal of Ecology and Environment
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• v.35 no.2 s.98
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• pp.133-140
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• 2002

This study was performed in lab scaled oxidation pond. The removal efficiency of pollutant on the influence of changes of hydraulic retention time and pond style was investigated. The correlation between organic removal efficiency and dissolved oxygen concentration on algal photosynthesis showed the light time revealed a higher relationship more than the dark time, and the squares of the correlation coefficient of 15 days retention time were higher than that of 5 days in single pond. The variation of dissolved oxygen concentration of a series pond was from 4.2 to 19.8 mg/l under 5 days retention time, the concentration of dissolved oxygen increased with increasing step of series pond. Between the single pond and a series of pond system, a series of pond system showed better organic removal efficiency. Average removal efficiency range of $TBOD_5$ and $SBOD_5$ was $49{\sim}83%$ and $87{\sim}92%$, respectively. Algae should be removed appropriately to increase the removal efficiency of organic matter.

• Korean Chemical Engineering Research
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• v.52 no.1
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• pp.8-16
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• 2014

Microalgae have been considered as a promising microorganism in the field of bio-industry due to their abilities to fix carbon dioxide as well as biosynthesize valuable secondary metabolites. Of many lighting sources for microalgal cultivation, LED (Lighting Emitting Diode) has been emerged as the appropriate choice with multiple advantages over the conventional bulbs. However, it is only in recent years that we have witnessed the possibility of application of LED into microalgae cultivation system. LED will serve as an evolutionary lighting source for microalgae cultivation system and open the frontier for integrative bio-industries. In this paper, we present the comprehensive review on the recent trends of LED applications into microalgal biotechnology.