• ALGAE
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• v.18 no.2
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• pp.135-143
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• 2003

The seasonal dynamics of phytoplankton and trophic state were evaluated weekly at three sites in the Lake Unmoon from May to November 2001. The seasonal succession pattern of phytoplankton community in the Lake Unmoon showed that the dominant species were; i) diatoms during the late spring, ii) dinoflagellates in June, iii) blue green algae, diatoms and dinoflagellates in July, iv) green algae and blue green algae in August, v) blue green algae in September and early November, and vi) diatoms in November. Members of Microcystis were dominant from middle August to late October and members of Aulocoseira appeared as important species in autumn in the Lake Unmoon. The concentration of chlorophyll-a ranged from 2.4 to 23.0 mg ${\cdot}m^{-3}$ (average: 8.6 mg ${\cdot}m^{-3}$) during the study period. Concentrations of total phosphorus were high during the period from July to November with the maximum of 0.028 mg ${\cdot} l^{-1}$. The average N/P ratio was 121, indicating that concentrations of phosphorus may determine the high algal biomass in the Lake Unmoon. Concentrations of silicate were higher in the Lake Unmoon (average value: 10.016 mg ${\cdot}$ l-) than in other lakes (average values: 1.074-4.408 mg ${\cdot}$ l-), suggesting high potential of diatom growth. The average trophic state index in the Lake Unmoon was 52, which was close to eutrophic state, and the trophic state trend was increasing steadily since 1999.

• Korean Journal of Environmental Biology
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• v.23 no.2 s.58
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• pp.206-213
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• 2005

The diurnal and seasonal variations of antioxidative enzyme activity and the O-J-I-P transients were investigated from the leaves of Crinum asiaticum var. japonicum under winter stress in natural habitat, in order to diagnose quantitatively physiological states of plants under stresses. The activities of superoxide dismutase and peroxidase increased slightly in winter. Especially, peroxidase acitivity was higher at dawn and night in winter and some isoforms were detected only in early winter. In the O-J-I-P transients, the fluorescence intensity of J, I, P steps decreased significantly in winter season, contrary to its high value in summer season. Of the chlorophyll fluorescence parameters derived from the O-J-I-P transients, Fm and $\Phi_{po}$ decreased with the increase of ABS/RC depending on temperature drop in winter.

• Journal of Marine Bioscience and Biotechnology
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• v.12 no.1
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• pp.40-49
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• 2020

This article emphasized the physiological characteristics of the selected marine microalgal strains obtained from the culture collection of the National Marine Biodiversity Institute of Korea (MABIK). Therefore, in this study, 13 different marine microalgal strains belonging to the phylum Chlorophyta were analyzed for the composition of fatty acids, elements, photosynthetic pigments, and monosaccharides, as well as the lipid and protein contents. The results presented that the primary fatty acids were palmitic (C_16:0), palmitoleic (C_16:1 n-7), stearic (C_18:0), oleic (C_18:1 n-9), linoleic (C_18:2 n-6), and α-linolenic (ALA, C_18:3 n-3) acid in the evaluated microalgae. The lipid contents of heterotrophically grown strains ranged from 15.1% to 20.4%. The calorific values of the strains were between 17.4 MJ kg^-1 and 21.3 MJ kg^-1. The major monosaccharides were galactose, glucose, and mannose, while the primary photosynthetic pigments were chlorophyll-a (Chla), chlorophyll-b (Chlb), and lutein, respectively. Based on the results, the microalgal strains showed high potentials in the use of microalgae-based technologies to produce biochemicals, food, and renewable fuels as they are rich in sustainable sources of high-value bio-compounds, such as antioxidants, carbohydrates, and fatty acids.

• Magazine of the Korean Society of Agricultural Engineers
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• v.32 no.3
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• pp.116-129
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• 1990

A rational management of water resources in estuary reservoirs necessiates the prediction of water quality. In this study, a multiple box model for the water quality prediction was developed as a tool for the purpose of examining an adequate way to improve and maintain the water quality. Some submodels that are suitable for simulating the mixing behavior of pollutant materials in a lake were considered in this model. The model was appiled for predicting water qualities of Haenam Esturay Reservoir. The result from this study can be summarized as follows : 1.A water quality simulation model that can predict the 10-day mean value of water qualities was developed by adding some submodels that simulate the concentrations of chlorophyll-a, BOD, T-P and T-N to the existing Multiple Box Model representing the mixing and circulating of materials by the hydarulic action. 2.As input data for the model developed, the climatic data including precipitation, solar radiation, temperature, cloudness, wind speed and relative humidity, and the water buget records including the pumping discharge and the releasing discharge by drainage gate were ollected. The hydrologic data for the inflow discharge from the watershed was obtained by simulation with the aid of USDAUL-74/SNUA watershed model. Also the water quality data were measured at streams and the reservoir. 3.As a result of calibration and verification test by using four comonents of water quality such as Chlorophyll-a, BOD, T-P and T-N, it was found that the correlation coefficeints between the observed and the simulated water qualities showed greater than 0.6, therefore the capability of the model to simulate the water quality was proved. 4.The result based on the model application showed that the water quality of the Haenam Estuary Reservoir varies seasonally with the harmonic trend, however the water quality is good in winter and get worse in summer. Also it may be concluded that the current grarde of water quality in the Heanam Esutary Reservoir is ranked as grade 4 suitable only for the agricultutal use.

• Journal of Ecology and Environment
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• v.39 no.1
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• pp.81-90
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• 2016

This study was to investigate the effect of salt stress on physiological characteristics such as plant growth, photosynthesis, solutes related to osmoregulation of Beta vulgaris. A significant increase of dry weight was observed in 50 mM and 100 mM NaCl. The contents of Chl a, b and carotenoid were lower in NaCl treatments than the control. On 14 day after NaCl treatment, photosynthetic rate (P_N), the transpiration rate (E) and stomatal conductance of CO₂ (g_s) were reduced by NaCl treatment. On 28 day after NaCl treatment, the significant reduction in g_s and E was shown in NaCl 200 mM. However, P_N and water use efficiency (WUE) in all NaCl treatments showed higher value than that of control. Total ion contents (TIC) and osmolality were higher than the control. On 14 day after treatment, the contents of proline (Pro) increased significantly in 200 mM and 300 mM NaCl concentration compared with control, whereas on 28 day in all treatments it was lower than that of the control. The contents of glycine betaine (GB) increased with the increase of NaCl concentration. The contents of Na⁺, Cl^-, GB, osmolality and TIC increased with the increase of NaCl concentrations. These results suggested that under severe NaCl stress conditions, NaCl treatment did not induce photochemical inhibition on fluorescence in the leaves of B. vulgaris, but the reduction of chlorophyll contents was related in a decrease in leaf production. Furthermore, increased GB as well as Na⁺ and Cl^- contents resulted in a increase of osmolality, which can help to overcome NaCl stress.

• Journal of Environmental Science International
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• v.18 no.3
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• pp.289-298
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• 2009

The blue-green algae which caused odor problem in the tap water are difficult to precipitate in sedimentation basin and clogged the filter void rapidly. The studies of this paper were not only oxidation, coagulation and sedimentation processes for effectively removing blue-green algae but yellow clay and polyamine for verification as coagulants aids. The results of this research are summarized as follows: Higher ozone dose(C) and longer contact time(T) were needed for a high degree of removing blue-green algae efficiency. the removal rate of blue-green algae was proportional to the $C\times T$ value. The removal percent of chlorophyll-a by sedimentation and filter without pre-ozonation was about 75% but 1 mg/L pre-ozonation could increase the removal percent of chlorophyll-a to 99% and more pre-ozonation could remove completely. Though the removal efficiency of turbidity could increased by high dose of chlorination, the dissolved organic carbon was increased. More chlorine dose from 4 to 10 mg/L dissolved organic carbon was decreased. Using yellow clay as coagulant aids increased density of floc so the settling velocity of floc become rising but polyamine could not increase settling velocity of floc though it could formated large floc.

• Journal of Forest and Environmental Science
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• v.30 no.1
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• pp.120-125
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• 2014

Halophytes are plants of saline habitats that grow under conditions that may vary in extremes of temperatures (freezing to very hot), water availability (drought to water logging) and salinity (mild to almost saturation). Halophytes may also face sudden micro-environmental variations within their habitats. In this study, we examine some of the factors that determine the ability of seeds of Artemisia fukudo to germinate when conditions are optimal for seedling growth and survival. Germination percentage was the highest at 77.5% when treated in 0% seawater and seedling growth was best in 0% seawater plug cell tray. Physiological quality (chlorophyll contents) and mean germination time were best in the condition in which seeds were treated with 0% seawater (control). Germination performance index in the control group showed the highest value to 3.8. Seedling growth, seedling vigor index in the length of seedling growth andthe relative growth rate were the highest values of 0.76 cm, 1.43, 0.0099, respectively.

• Korean Journal of Human Ecology
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• v.24 no.6
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• pp.859-871
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• 2015

The purpose of this study is to examine the influence of the pigment characteristic and changes in dying conditions on the dying properties by extracting Chelidonium majus var. asiaticum using distilled water and ethanol as solvents. Changes in dying conditions include variations in dye concentrations, dyeing temperatures and time on dye uptake, and K/S Value was compared according to these changes. Additionally, color changes were observed through mordant. Ultraviolet-visible spectrum was used to investigate the pigment characteristic, and as a result, tannin was identified in distilled-water-extract, whereas berberine and chlorophyll were identified in ethanol-extract. In FT-IR analysis, tannin in distilled-water-extract was verified as hydrolyzable tannin. For ethanol extract, chlorophyll was verified through absorption band of C-H, which is aliphatic spectrum around $2920cm^{-1}$ and $2850cm^{-1}$. From GC/MS analysis, oil components as well as terpine compounds were detected in ethanol-extract, and this, in turn, brings expectation regarding functionality. When dying in silk, dye uptake increased as concentration of the extract increased, and the optimum dyeing temperature and time were $40^{\circ}C$ and 60 minutes respectively. Dyed fabrics' colors were all basically Y-series colors, and adjustment in brightness and revelation of khaki color were also available depending on the type of the mordant. Color fastness, except for washing fastness, was good in silk dyed with distilled-water-extract. Thus, it can be concluded that by selecting the right extracting method and by doing proper dyeing and mordant according to the needs, these dyed fabrics can be used as eco-friendly, functional clothing material.

• Korean Journal of Food Science and Technology
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• v.13 no.1
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• pp.25-29
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• 1981

Harvested asparagus, Viking variety, was stored in normal and controlled atmosphere with and without ‘Butts in water’ to extend shelf life of fresh asparagus. Controlled atmosphere storage significantly reduced bacterial soft rot of asparagus. When asparagus was stored in controlled atmosphere in combination with ‘Butts in water’, asparagus spears could be stored over 3 weeks without noticeable soft rot. Texture of stored asparagus, as measured by Instron and fiber analysis, became tougher as the storage time was extended. Increase of fiber content in asparagus was significantly reduced by controlled atmosphere storage and fiber content actually decreased in asparagus stored in controlled atmosphere in combination with ‘Butts in water’. Asparagus stored in controlled atmosphere had markedly less chlorophyll destruction than that in normal atmosphere. Reflectance color values of stored asparagus were closely associated with chlorophyll content in asparagus. Considering all quality factors of stored asparagus, controlled atmosphere in combination with ‘Butts in water’ was the best storage method to maintain overall quality of harvested asparagus over 3 weeks.

• Applied Biological Chemistry
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• v.31 no.3
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• pp.284-291
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• 1988

To establish the evaluation method of Korean green tea, the correlation between physicochemical characteristics and sensory scores by the expert panels were investigated using 15 kinds of green tea manufactured in 1985 from Korea, Taiwan and Japan. Tannin, caffeine and total free amino acid contents of Korean green tea are higher than foreign ones, but the chlorophyll content is the highest in Japanese high grade green tea. Sixteen free amino acids including theanine were identified, and theanine, glutamic acid, aspartic acid and arginine contents which affect the brothy taste of green tea infusion were highest in Korean green tea. Sensory score for the color of Korean green tea infusion were lower than Japanese tea, but the flavor and taste were the best. In multiple regression analysis, the quality affecting factors of the green tea were elucidated as the caffeine$(X_1)$, chlorophyll b$(X_2)$, total free amino acid contents$(X_3)$, and L value$(X_4)$ of green tea infusion. The regression equation was expressed as $Y=-21.5820+2.1691X_1+0.0130X_2+0.2314X_3-0.0001X_4$ and then $R^2$ was 0.8919.