• Journal of the Korean Society of Groundwater Environment
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• v.1 no.1
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• pp.33-50
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• 1994

The Hydrogeologic data of 455 water wells comprising geologic log and aquifer test were analyzed to determine hydrogeologic characteristics of the Cheju island. The groundwater. of the Cheju island is occurred in unconsolidated pyroclastic deposits and crinker interbedded in highly jointed basaltic and andesic rocks as high level, basal and parabasal types under unconfined condition. The average transmissivity and specific yield of the aquifer are at about 29,300㎡/day and 0.12 respectively, The total storage of groundwater is estimated about 44 billion cubic meters. Average annual precipitation is about 3,390 million ㎥ among which average recharge is estimated for 1,494 million ㎥ being equivalent 44.1% of total annual precipitation with 638 million ㎥ of runoff and 1,256 million ㎥ of evapotranspiration. Based on groundwater budget analysis, the sustainable yield is about 620 million ㎥(41% of annual recharge)and rest is discharging into the sea. The geologic logs of recently drilled thermal water wells indicate that very low-permeable marine sediments(Sehwa-ri formation) composed of loosely cemented sandy silt derived from mainly volcanic ashes at the 1st stage volcanic activity of the area is situated at the 120${\pm}$68m below sea level. Another low-permeable sedimentary rock called Seogipo-formation which is deemed younger than the former marine sediment is occured at the area covering north-west and western part of the Cheju island at the ${\pm}$70m below sea level. If these impermeable beds art distributed as a basal formation of fresh water zone of the Cheju island, the most of groundwater in the Cheju island will be para-basal type. These formations will be one of the most important hydrogeologic boundary and groundwater occurences in the area.

• Korean Journal of Weed Science
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• v.12 no.4
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• pp.352-361
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• 1992

The identification of the stoneworts, euglenoids and diatoms which were collected from paddy rice fields was conducted in 1991. In the division Charophyta. Chara braunii Gmelin was identified. Two species in the genus Euglena, 1 species in the genus Phacus and 3 species in the genus Trachelomonas were identified in the division Eugrenophyta. The total number of species identified as the diatoms was 21 species in 6 families including 5 species in the Coscinodiscaceae, 3 species in the Fragilariaceae, 1 species in the Achanthaceae, 9 species in the Naviculaceae, 1 species in the Cymbellaceae and 2 species in the Nitzschiaceae. Generally, a concentrated population of Eulgena on paddy water caused green water blooms, but the color of the water blooms at the cyst formation stage was changed to red. In soil flakes with brown tint, the diatoms belonging to the order Pennales were numerous in microscopic view.

• Geophysics and Geophysical Exploration
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• v.14 no.4
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• pp.324-334
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• 2011

Seismic wave velocity change has been monitored due to the accumulation of micro-cracks by uniaxial loads on the rock samples from Seokmo Island with stepwise increase in 5 stages. After the load was applied up to 95% of UCS, P- and S-wave velocities varied in ranges of 0.9 ~ 18.3% and 2.8 ~ 14.8% of fresh rock sample velocities, respectively. Unlike seismic velocity of the dry rock samples that showed overall decreases after the loading, velocity changes of saturated rock samples were much more complicated. These seemed to be due to the mixture of two contradictory mechanisms; i.e. accumulation of micro-crack causes an increase in porosity and a decrease in wave velocity, while saturation causes an increase in wave velocity. Most of tested rocks showed a trend of velocity increase with low axial load and then velocity decrease at later stages. Starting stage of velocity decrease differs from samples to samples. After the failure of rock occurred, noticeable increases of porosity and decreases of wave velocity have been observed. It showed overall trend that the more the quartz contents and the lower the silicate, the higher the Young's modulus.

• Journal of Aquaculture
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• v.11 no.1
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• pp.99-103
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• 1998

Artemia often observed as a co-existing organism in the mass culture tank of marine rotifer. The rotifer and Atremia are commonly used as food organisms in the marine fish larvae rearing. In this study, interspecific relation between the rotifer Brachionus rotundiformis (formely called S-type) and anostracan Artemia of the two developmental stages (0 and 19 day old after hatching) were investigated in the larboratory. The population growth of B. rotundiformis and one of the stage (nauplius or adult) of Artemia in mixed culture was compared with that of each single species culture. Culture period was 16 days. Every two days, the number of organisms in each species was counted and transferred to a fresh medium containing $7{\times}10^5$cells/ml of food Nannochloropsis oculata. Culture volume, temperature, salinity and photoperiod were set at 40ml, $25^{\circ}C.$, 22ppt and 24h all dark except to observation time, respectively. The rotifer population growth was greatly decreased by co-existence with Artemia. The coexisting Artemia suppressed the rotifer population growth due to it's high filtering speed for food (N. oculata). This study suggested that contamination by Artemia must be prevented for the stable rotifer production in the rotifer mass culture tank.

• Korean journal of applied entomology
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• v.11 no.2
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• pp.55-60
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• 1972

The study has been carried to investigate the nature of resistance in rice varieties against bacterial leaf blight caused by Xanthomonas oryzae (Uyeda et. Ishiyama) Dowson. In this study, differences on several morphological histological and bacterial growth in rice leaf extract from different varieties were examined. Shirogane and Norm 6 as resistant varieties, Paldal as moderately resistant, and Jinheung, Kimmaze and Suwon 213 as susceptible varieties were used throughout the experiment. 1. Susceptible varieties Jinheung, Kimmaze have more hydathods in flag leaf than resistant varieties but there were no difference between resistant varieties and moderatly resistant varieties. 2. Average length of xylem vessel elements were 50r longer in leaf veins of susceptible varieties Jinheung, Kimnaze and Suwon 213 than those of resistant varieties, but there were no difference among Paldal, Norm 6 and Shirogane. 3. Kimmaze and Suwon 213 have larger diameter of xylem vessel elements than those of other varieties examined. However, it did not differ significantly between resistant varieries and susceptible varieties statistically. 4. Jinheung and Kimmaze have more secondary xylem vessels in root of 6-7th leaf stage than those of Shirogane and Norm 6. Suwon 213, however, showed least number of secondary xylem vessels exceptionally. 5. Leaf extract from resistnat variety Shirogane, suppressed bacterial growth significantly when compared with those from other varieties. 6. Bacterial growth in autoclaved leaf extract from resistant varieties and susceptible varieties did not show any noticeable difference. In general, fresh extract maintained more bacteria than in autoclaved extract after 48 hours of incubation period.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.1 no.2
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• pp.63-71
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• 1968

Salted and dried yellow corvenia(Pseudosciaena manchurica), so called 'Gul-bi', is one of nation-widely consuming fish foo::ls. It is suitable for a long term preservation and its pro-duce is also a great deal on sea food processing in this country. The texture of 'Gul-bi', however, have often appeared to be a delicate factor for the quality of the product. The loss or dislocation of fat in the tissue of the fish resulted by salting and drying is believed to profoundly relate to the texture of product. In this paper, the tissue of yellow corvenia and movement of fat were microscopically observed before salting, immediately after salting, and after drying and the results observed in the tissues dry salted, brine salted, and brine salted with the addition of BHA were compared. The cross section of yellow corvenia muscle showed that a distinctive border by connective tissue between white and red muscle could not be seen in general, and red muscle was surrounded by hypodermic fatty tissues. In the tissue of fresh yellow corvenia, the fat was mainly distributed in hypodermic fat layer which located under the corium while rarely distributed in white muscle. It was found that some parts of the fat in the tissue were permeated into intermuscular tissue passing through the connective tissues during salting. The result Was the same in both dry-salting and brine-salting tissue. However, the fat translocated into intermuscular tissues disappeared during drying process in the salted without BHA tissues whereas in BHA added tissue. This result suggested that BHA may take a role of multiple effect in translocation of fat in tissues as well as in retarding oxidation. In an advanced stage of salted and dehydration, the muscle fibers were ajoined together and then limits between muscle fibers already became indistinguishable. And the migrated fat into intermuscular tissue aggregated around the connective tissue and are apt to gradually to flow out from the muscular system through these tissues.

• Journal of Bio-Environment Control
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• v.1 no.2
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• pp.169-174
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• 1992

This experiment was carried out to investigate the possibility of practical use of intermittent soaking system(ISS) in hydroponicaly growing tomato. There were four treatments which were NFT, Aeroponics, and ISS with 10 and 15 minute soaking intervals. 1. Plant height is highest in NFT, but main root length is longest in ISS. While stem diameter and leaf number were not significantly difference. 2. Fresh and dry weight were heavier in NFT than those of other systems at early growth stage, but the heavier in ISS system, the growth more develop. 3. In 43 days after treatment, the number of flowerlet was largest in aeroponics, and then ISS and NFT in order. Fruit weight per plant was also heaviest in aeroponics. 4. Average yield per plant were 1929.1g in aeroponics, 1475.2g in ISS with 10 minute soaking interval, 1276.2g in NFT and 1084.8g in ISS with 15 minute soaking interval. 5. Average fruit number per plant were 11.0 in aeroponics, 9.7 in NFT, 8.3 in ISS with 15 minute soaking interval, and 7.7 in ISS with 10 minute soaking interval. Average fruit weight were 192.9g in aeroponics, 172.4g in ISS with 10 minute soaking interval, 134.0g in NFT and 126.0g in ISS with 15 minute soaking interval. 6. Average fruit length was longer in aeroponics and ISS with 10 minute soaking interval than in the NFT and ISS with 15 minute soaking interval. Average fruit width was similarly wider in NFT, aeroponics and ISS with 10 minute soaking interval than in ISS with 15 minute soaking interval.

• Journal of Bio-Environment Control
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• v.19 no.4
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• pp.210-216
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• 2010

This study was carried out to investigate the plant growth of various foliage plants affected by the nutrient solution strength. Ficus benjamina, Hedera helix, Philodendron tatei, Rhapis excelsa, Spathiphyllum spp. were used in this experiment. The Sonneveld solution was diluted to 0, 1/4, 1/2, and 1 folds and applied through a subirrigation system. Plant height and width, leaf number, leaf area, fresh and dry weights of shoots were measured to compare the responses to the different treatments. The required amounts for nutrients were different among the various foliage plants. The growth of Ficus and Philodendron was improved as the nutrient solution strength got higher, but that of Hedera and Spathiphyllum showed the best growth in the lower nutrient solution strength of 1/4 and 1/2 folds. The growth of Rhapis was improved in the nutrient solution strength of 1 fold but the other treatments did not affect on plant growth. N, P, and K were the most important nutrients that had influence on the growth of the foliage plants in this study. There was not an accurate criterion for fertilization and irrigation to each foliage plant. Moreover, the foliage plants grew slowly during the early stage and this period must be shortened for commercial production. Therefore, the experiment was executed to make up these defects. The plants applied with proper strength of Sonneveld solution grew faster and had better quality.

• Journal of Bio-Environment Control
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• v.26 no.4
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• pp.310-316
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• 2017

This study was analyzed the effects of boron (B), calcium (Ca), silicon (Si) on quality and shelf life of 'Unicorn' cherry tomato at the light red maturity-stage. The storage conditions were modified atmosphere packaging (MAP) by oxygen transmission rate (OTR) packaging film at $5^{\circ}C$, $11^{\circ}C$, and $24^{\circ}C$. Respiration and ethylene production were the lowest in B + Ca + Si -treated tomato fruits. The lowest fresh weight loss and the longest shelf life resulted from the B + Ca + Si treatment. And the firmness was enhanced by B + Ca + Si treatment at harvest time, and it was retained after storage at $5^{\circ}C$, $11^{\circ}C$, and $24^{\circ}C$. Significantly lower soluble solids, lycopene, and color development were found at B + Ca + Si-treated tomato fruits compared with control after storage. Moreover, the highest titratable acidity and vitamin C content were observed in B + Ca + Si-treated tomato fruits after storage. From the above results, it was concluded that B + Ca + Si combined treatment can delay the maturity of cherry tomato after harvesting, and retained the firmness and prolong the shelf life.

• Journal of Plant Biotechnology
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• v.1 no.1
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• pp.1-7
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• 1999

Large-scale cultures of plant cell, tissue, and organ have been achieved by using BTBB. When different sized BTBBs (5 L, 20 L, 100 L, 300 L, and 500 L) were tested for the culture of yew cells (Taxus cuspidata Sieb. et Zucc.), cell growth increment reached to 94.5% in SCV after 24 days of culture with 30% of inoculation cell density. However, there were some variations in the production of taxol and its derivatives among the BTBBs of different size. Approximate 4 ㎎/l of taxol and 84 ㎎/l of total taxanes were obtained by using a 500L BTBB after 6 weeks of culture. With a 20L BTBB, about 20,000 cuttings of virus-free potatoes (cv. Dejima) could be obtained by inoculating 128 explants and maintaining 8 weeks under 16 hr light illumination. The frequency of ex vitro rooting of the cuttings revealed as more than 99% under 30% shade. By incorporating two-stage culture process consisting of multiple bulblet formation in solid medium and bulblet development in liquid medium, mass propagation of lily through bioreactor seemed to be possible. In the case of 'Marcopolo', the growth of mini-bulblets in BTBB was nearly 10 folds faster than that of the solid medium. Time course study revealed that maximum MAR yield of ginseng (Panax ginseng C. A. Meyer) in a 5 L and 20 L BTBB after 8 weeks of culture was 500 g and 2.2 ㎏, respectively. By cutting the MAR once and/or twice during the culture, the yield of root biomass could be increased more than 50% in fresh weight at the time of harvest. With initial inoculum of 500 g of sliced MAR in a 500 L BTBB, 74.8 ㎏ of adventitious root mass was obtained after 8 weeks of culture. The average content of total ginseng saponin obtained from small-scale and/or pilotscale BTBBs was approximately 1% per gram dry weight. Based on our results, we suggest that large-scale cultures of plant cell, tissue, and organ using BTBB system should be quite a feasible approach when compared with conventional method of tissue culture.