• KOREAN JOURNAL OF CROP SCIENCE
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• v.42 no.6
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• pp.699-705
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• 1997

This experiment was conducted to find out an optimum direct seeding date for rice in the southern alpine area of Korea as direct seeding method being considered as the most labor-saving method. A cultivar which was sprouted, Keumobyeo, was sown on the surface of flooded paddy from April 25 to May 15 with 5-day interval. The growth characters such plant height, tiller numbers, yield and its components as well as air temperatures were observed. Earlier sowing showed longer plant height and greater tillers than later sowing. Accumulated temperatures in the different growth stages varied from 1,010 to 1,052$^{\circ}C$ during the period from seeding date to maximum tillering stage, and from 1,785 to 1,846$^{\circ}C$ during the period from seeding to heading dates. The growth of rice sown up to May 5 showed comparatively good when compared to that of machine-transplanted rice, even though the grain yield was not competitive to that of machine-transplanted rice. Highly negative correlation coefficients were found between accumulated temperature during the period of first 30 days after seeding dates and the number of panicles, the number of spikelets per square meter, and grain yield. Regression equation between direct seeding date(X) and yield(Y;MT /ha) was $\hat{Y}$ =3.80990＋0.06207X-0.00174 $X^2$($R^2$=0.704), from which optimum seeding date for direct seeding method in alpine area was estimated to be on April 25 to May 1.

• Journal of agriculture & life science
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• v.46 no.1
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• pp.195-206
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• 2012

This study is about an analysis of surplus solar energy by important greenhouse types as well as setting temperature different by using Typical Meteorological Year data which was secured in order to provide basic data for designing an optimum thermal storage system to accumulate surplus solar energy generating in greenhouses during the daytime. Depending on the setting temperatures of $15{\sim}19^{\circ}C$ for greenhouse heating during day and night, surplus heat amounts were varied at the rate of about $0.2{\sim}6.9%/4^{\circ}C$ with some variations according to the greenhouse types and regions. On the other hand, the variations of supplemental heat requirements were about $29.7{\sim}50.0%/4^{\circ}C$. Depending on the setting temperatures for greenhouse ventilations(low $25{\sim}29^{\circ}C$ and high $27{\sim}31^{\circ}C$), surplus heat amounts were varied at the rate of about $-9.9{\sim}-35.6%/4^{\circ}C$ in auto-type greenhouse. But in single-type greenhouses, they were about $-5.1{\sim}-13.4%/4^{\circ}C$. There were not significant changes in supplemental heat amounts depending on setting temperatures of ventilation for both greenhouse types and regions.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.12 no.1
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• pp.24-31
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• 2007

Global fates of polychlorinated biphenyl(PCB) were investigated with a fugacity based multimedia transport and fate model, Globe-POP(persistent organic pollutant). The accumulation of PCB was directly affected by the emission patterns of PCB into the atmosphere and surface areas of environmental compartments. Partition coefficients and reaction rates also influenced on the accumulation patterns of PCB. The emission patterns of PCB in 10 climate zones were consistent for the past 70 years, while the contribution of PCB in high-latitude zones to the globe has increased by cold condensation. Considering the amounts of emission and accumulation of PCB, the North temperature zone is regarded as an important source and sink of PCB. Meanwhile, in spite of no significant sources, POPs accumulate in Antarctic environments mainly due to extremely low temperature. Finally we suggested that a global water balance accounting for snow/ice should be incorporated into multimedia environmental models for high-latitude zones and polar regions with the seasonal snow pack and/or permanent ice caps. The modified model will be useful to evaluate the influence of climate change on the fate of POPs.

• Journal of Bio-Environment Control
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• v.30 no.4
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• pp.295-303
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• 2021

We analyzed berry skin coloration, anthocyanin accumulation, and plant hormone contents in berry skins to determine the effect of night temperature at veraison on berry skin coloration in 'Kyoho' grapevines (Vitis labruscana L.). Vines were grown under 21, 24, and 27℃ at night for 20 days at veraison, from 40 to 60 days after full bloom (DAFB). Berry skin coloration of 'Kyoho' grapes was more suppressed in 27℃ treated vines, followed by that in 24℃ treated vines, than that in 21℃ treated vines. Cluster and berry weight and soluble solids content was lower in 24 and 27℃ treated vines than in 21℃ treated vines. Anthocyanin started to accumulate from 60 DAFB in berry skin of 21℃ treated vines, and malvidin and total anthocyanin content increased until 100 DAFB. The total and most of the individual anthocyanins decreased in 24 and 27℃ treated vines; however, peonidin did not decrease in 24℃ treated vines compared to that in 21℃ treated vines. Abscisic acid (ABA) peaked at veraison in berry skins of 21℃ treated vines and decreased thereafter until 100 DAFB. The increase in ABA content was inhibited in berry skins of 24 and 27℃ treated vines. Gibberellin (GA) content in berry skins decreased rapidly at veraison, with the decrease being slower under 27℃ than under 21℃. ABA/GA in berry skins of 21℃ treated vines peaked at 60 DAFB and decreased thereafter until 100 DAFB. However, ABA/GA decreased in berry skins of 24 and 27℃ treated vines, with reduced anthocyanin accumulation. Therefore, high night temperature (above 24℃) at veraison suppressed the berry skin coloration of 'Kyoho' grapes with changes in anthocyanin contents and composition due to the decrease in ABA/GA ratio and fruit soluble solids contents.

• Journal of Life Science
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• v.14 no.1
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• pp.131-140
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• 2004

T7 bacteriophage gp4 is the replicative DNA helicase that unwinds double-stranded DNA by utilizing dTTP hydrolysis energy. The quaternary structure of the active form of T7 helicase is a hexameric ring with a central channel. Single-stranded DNA passes through the central channel of the hexameric ring as the helicase translocates $5'\rightarrow3'$ along the single-stranded DNA. The DNA unwinding was measured by rapid kinetic methods and showed a lag before the single-stranded DNA started to accumulate exponentially. This behavior was analyzed by a kinetic stepping model for the unwinding process. The observed lag phase increased as predicted by the model with increasing double-stranded DNA length. Trap DNA added in the reaction had no effect on the amplitudes of double-stranded DNA unwound, indicating that the $\tau7$ helicase is a highly processive helicase. Global fitting of the kinetic data to the stepping model provided a kinetic step size of 10-11 bp/step with a rate of $3.7 s^{-1}$ per step. Both the mechanism of DNA unwinding and dTTP hydrolysis and the coupling between the two are unaffected by temperature from $4∼37^{\circ}C$. Thus, the kinetic stepping for dsDNA unwinding is an inherent property of tile replicative DNA helicase.

• Journal of the Korean Society of Food Science and Nutrition
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• v.14 no.2
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• pp.117-122
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• 1985

The effects of various factors on the color stability of plum nectar were studied. The data showed that pH and temperature were the most important factors affecting the rate of color loss. The concentration of ascorbic acid affected the rate of color loss in plum nectar. Although the color loss could be influenced by the presence of sugars and their degradation products such as 5-hydroxymethyl-2-furfural(HMF), HMF did not accumulate in sufficient amounts during the storage in the plum nectar to affect appreciably the degradation rate. The pigment was very unstable in the fermented juice and its. spectrophotometric spectrum was changed differently from that of natural plum color material. Materials present in plum nectar itself apparently have an appreciable effect on the rate of color loss.

• Journal of Ecology and Environment
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• v.43 no.4
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• pp.341-351
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• 2019

Background: Standing biomass, litter production, rate of litter decomposition, amount of litter on forest floor, and amount of soil organic carbon distribution were investigated from March 2016 to November 2018 in order to evaluate the ecosystem value through organic carbon distribution in the Pinus densiflora forest at Namsan, Seoul Metropolitan City. Results: The amount of organic carbon in the Pinus densiflora forest was 261.09 ton C ha^-1 during the research period, and fixed organic carbon in plant through net photosynthesis was 3.2 ton C ha^-1 year^-1. The organic carbon in plant was 62.77 ton C ha^-1 (24.04%), in litter on the forest floor was 3.65 ton C ha^-1 (1.40%), and in soil was 194.67 ton C ha^-1 (74.56%). The value of plant, litter on forest floor, and soil organic carbon distribution were each 6,277,000 won ha^-1, 365, 000 won ha^-1, and 19,467,000 won ha^-1. The value per ton of fixed organic carbon in plant through net photosynthesis was 320,000 won ha^-1 year^-1 and the value of ecosystem services stored in carbon in the Namsan forest ecosystem was about 26.1 million won ha^-1 for 3 years. Conclusions: The results of this study suggest that the pine forests of Namsan rapidly decompose leaves due to the high atmospheric temperature and accumulate a large amount of organic carbon in the soil to provide climate control regulatory service function.

• Journal of Navigation and Port Research
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• v.42 no.1
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• pp.9-16
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• 2018

The development of limited petroleum resources for use with mankind inevitably explores and seeks to develop oil fields in the deep sea area, under the rise of the oil prices market situation. The use of Oceanic Thermal Energy Conversion (OTEC) technology, which operates the power generation facility using the temperature differences between the deep water and the surface water, is progressing actively as a trend to follow. In this study, the application of the Discharged Thermal Energy Conversion (DTEC) was designed and analyzed under the condition that the supply condition of seawater used in the FPSO installed in the deep sea area is changed up to 400m depth. In this case, it was confirmed that the design of the system that can generate more electric power according to the depth of water is confirmed, by thus applying the DTEC system by taking the cooling water at a deeper water depth than the existing design water depth. The FPSO considers the similarity of the OTEC power generation facilities, and will apply the DTEC system to FPSO in the deep sea area to accumulate technology and the conversion to further utilize the OTEC power generation facilities after the end of life cycle of oil production, which could be a solution to two important issues, namely, resource development and sustainable development.

• Korean Journal of Remote Sensing
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• v.37 no.5_1
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• pp.1199-1206
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• 2021

Accordingly, attention is also being paid to the agricultural use of remote sensing technique that non-destructively and continuously detects the growth and physiological status of crops. However, when remote sensing techniques are used for crop monitoring, it is possible to continuously monitor the abnormality of crops in real time. For this, standard growth information of crops is required and relative growth considering the cultivation environment must be identified. With the relationship between GDD (Growing Degree Days), which is the cumulative temperature related to crop growth obtained from ideal cultivation management, and the vegetation index as standard growth information, compared with the vegetation index observed with the spectralreflectance sensor(SRS_NDVI & SRS_PRI) in each rice paddy treated with standard cultivation management and non-fertilized, it was quantitatively identified as a time series. In the future, it is necessary to accumulate a database targeting various climatic conditions and varieties in the standard cultivation management area to establish a more reliable standard growth information.

• Journal of Radiopharmaceuticals and Molecular Probes
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• v.5 no.1
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• pp.18-25
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• 2019

2-Nitroimidazole derivatives have been reported to accumulate in hypoxic tissue. We prepared a novel $^{99m}Tc-MAG_3$-2-nitroimidazole and evaluated the feasibility for hypoxia imaging agent. $Bz-MAG_3$-2-nitroimidazole was synthesized by direct coupling of $Bz-MAG_3$ and 2-nitroimidazole using dicyclohexylcarbodiimide. $Bz-MAG_3$-2-nitroimidazole was labeled with $^{99m}Tc$ in the presence of tartaric acid and $SnCl_2-2H_2O$ at $100^{\circ}C$ for 30 min. And the reaction mixture was purified by $C_{18}$ Sep-pak cartridge. The labeling efficiency and the radiochemical purity were checked by ITLC-SG/acetonitrile. The tumor was grown in balb/c mice for 8~13 days after the subcutaneous injection of tumor cells, CT-26 (murine colon adenocarcinoma cell). Biodistribution study and tumor autoradiography were performed in the xenografted mice after i.v injection of 74 kBq/0.1 mL and 19 MBq/0.1 mL of $^{99m}Tc-MAG_3$-2-nitroimidazole, respectively. In vivo images of $^{99m}Tc-MAG_3$-2-nitroimidazole in tumor bearing mice were obtained 1.5 hr post injection. The labeling efficiency was $45{\pm}20%$ and the radiochemical purity after purification was over 95%. Paper electrophoresis confirmed negative charge of $^{99m}Tc-MAG_3$-2-nitroimidazole. $^{99m}Tc-MAG_3$-2-nitroimidazole was very stable at room temperature and its protein binding was 53%. The $^{99m}Tc-MAG_3$-2-nitroimidazole exhibited high uptake in the liver, stomach and intestine. In biodistribution study using tumor bearing mice, the uptakes (% ID/g) of the tumor were $0.5{\pm}0.1$, $0.4{\pm}0.0$, $0.2{\pm}0.1$ and $0.1{\pm}0.1$ at 5, 15, 30 min and 4 hrs. Tumor/muscle ratio were $1.4{\pm}0.1$, $2.2{\pm}0.83$, $3.0{\pm}0.9$, and 3.7 (n=2) for 5, 15, 30 min and 4 hrs. The uptake in hypoxic area was found higher than in non-hypoxic area of tumor tissue by autoradiography. In vivo images showed the relatively faint uptake to the hypoxic tumor region. $^{99m}Tc-MAG_3$-2-nitroimidazole was successfully synthesized and found feasible for imaging hypoxia.