• Korean Chemical Engineering Research
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• v.54 no.3
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• pp.310-314
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• 2016

The search for natural antioxidants as alternatives to synthetic products is growing. Microalgae have emerged as a source of natural antioxidants with significant and diverse health-promoting properties. In this study, the effects of hot-water extraction conditions on total polyphenol compounds (TPC) production were investigated for lipid extracted microalgae (LEA). In order to enhance the polyphenol productivity, the extraction variables including solvents, temperature, time and ethanol concentration were optimized. The results showed hot-water extraction provided a higher extraction efficiency than the organic solvents and extraction at high temperatures showed a better extraction efficiency. While hot-water extract showed a higher extraction efficiency compared to 98% ethanol extraction, the mixture of water and ethanol (40:60 v/v) showed the highest production of polyphenols. The maximum polyphenols of 3.35 mg GAE (gallic acid equivalent)/g DM were obtained at the optimized extraction time of 10 min, $100^{\circ}C$ and 40% ethanol, respectively. Although Tetraselmis KCTC 12236BP was preprocessed by hexane to remove lipid for bio-diesel production, the results showed LEA contains relatively high level of polyphenols compared to untreated microalgae which can be used in the production of value-added materials. The predictions obtained from the developed Peleg's model were compared with the experimental data under the same operating conditions. The predicted and experimental data were consistent, indicating the reliability of the model.

• Korean journal of applied entomology
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• v.26 no.1 s.70
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• pp.9-12
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• 1987

The control effect of three systemic insecticides on the brown planthopper; carbofuran 3G, disyston 3G, and omethoate 50% EC, which have been used to control of the insect pests on rice crop in its early growing season, were evaluated. Soil incorporation and water broadcasting methods before transplanation were used for carbofuran and disyston, and omethoate was applied as foliar spray 6 days after transplanation. Ten pairs of newly emerged adults were inoculated on June 11, 21, July 2, 11, and 25. The number of the brown planthoppers on the rice plane were examined by means of direct reading. The three insecticides were effective for about ten days regardless of application methods, thereafter, fail to control of the insects except carbofuran. By means of soil incorporation, carbofuran could control the insects effectively for 45 days or longer, and it seemed to be able to control the progeny of the migrated brown planthopper until middle or late June.

• Korean Journal of Agricultural Science
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• v.8 no.1
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• pp.44-50
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• 1981

This experiments was carried out to evaluate the effect of nitrogen retention on different levels of crude protein intake according to live weight, and the crude protein and urea content in serum of the Korean native goat. The results obtained are as follows: 1. When the female goat at 8 months age (14kg) had taken nitrogen free diet, the content of endogenous urinary nitrogen was 1.29g and endogenous fecal nitrogen was 1.27g per day. Therefore, the goat needs minimum level of crude protein per day. 2. When the thermometer checked below-$10^{\circ}C$, the nitrogen retention rate showed minus reaction in spite of 20% crude protein level. This suggested that the low temperature was consumed higher energy to maintain the body. 3. The nitrogen retention rate of the pregnant female goat of 20kg live weight, however, decreased as compared with the growing goat and was 17~20%. 4. According to the levels of crude protein were lower, crude protein and urinary nitrogen contents in serum were greatly decreased.

• Proceedings of the Korea Association of Crystal Growth Conference
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• 1996.06a
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• pp.522-522
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• 1996

An investigation of the effects of transverse magnetic field and Peltier effect on melt convection and macrosegregation in vertical Bridgman crystal grosth of Te doped InSb was been carried out by means of microstructure observation, Hall measurement, electrical resistivity measurement and X-ray analysis. Before the experiments, Interface stability, convective instability and suppression of convection by magnetic field were calculated theoretically. After doping 1018, 1019 cm-3 Te in InSb, the temperature of Bridgman furnace was set up at $650^{\circ}C$. The samples were grown in I.D. 11mm, 100mm high quartz tube. The velocity of growth was about 2${\mu}{\textrm}{m}$/sec. In order to obtain the suppression of convection by magnetic field in the middle of growth, 2-4KG magnetic field was set on the melt. For searching of the shape of solid-liquid interface and the actual velocity of crystal growth, let 2A current flow from solid to liquid for 1second every 50seconds repeatedly (Peltier effect). The grown InSb was polycrystal, and each grain was very sharp. There was no much difference between the sample with and without magnetic field at a point of view of microstructure. For the sample with Peltier effect, the Peltier marks(striation) were observed regularly as expected. Through these marks, it was found that the solid-liquid interface was flat and the actual growth velocity was about 1-2${\mu}{\textrm}{m}$/sec. On the ground of theoretical calculation, there is thermosolutal convection in the Te doped InSb melt without magnetic field in this growth condition. and if there is more than 1KG magnetic field, the convection is suppressed. Through this experiments, the effective distribution coefficients, koff, were 0.35 in the case of no magnetic field, and 0.45 when the magnetic field is 2KG, 0.7 at 4KG. It was found that the more magnetic field was applied, the more convection was suppressed. But there was some difference between the theoretical calculation and the experiment, the cause of the difference was thought due to the use of some approximated values in theoretical calculation. In addition to these results, the sample with Peltier effect showed unexpected result about the Te distribution in InSb. It looked like no convection and no macrosegregation. It was thought that the unexpected behavior was due to Peltier mark. that is, when the strong current flew the growing sample, the mark was formed by catching Te. As a result of the phenomena, the more Te containing thin layer was made. The layer ruled the Hall measurement. The values of resistivity and mobility of these samples were just a little than those of other reference. It was thought that the reason of this result was that these samples were due to polycrystal, that is, grain boundaries had an influence on this result.

• Journal of the Korean Academy of Esthetic Dentistry
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• v.22 no.1
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• pp.30-46
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• 2013

Porcelain fused to metal crown has been used mostly over the last 50 years for restorations in dentistry. However, the patients' awareness of aesthetic aspect, biocompatibility and the problems such as an allergy to metals led to the growing interest in the 'metal free restoration'. In particular, the price of the precious metals that have been mainly used to date has risen drastically, which made them impossible to play their role as oral restorative materials anymore, and in addition, the PFM restoration has intrinsic problems of chipping and fracture. Therefore, the CAD/CAM has been drawing more attention than ever due to the popular needs for the material that is more aesthetic and stronger for restoration of the molar implant. Considerations in carrying out the full zirconia restoration are as follows: 1) strength, 2) combination work, 3) light penetrability, 4) treatment of cracks, 5) the color reproducibility of the block, 6) the abrasivity of antagonistic tooth, 7) low temperature degradation. In this presentation, the color reproducibility of the block will be discussed. One of the biggest reasons for avoiding the full zirconia restoration is that it is difficult to reproduce the natural color compared to the conventional PFM restoration. Thus, many clinicians show reluctance due to the exposure of the ugly block when the coloring on the surface is removed after occlusal adjustment. From the experience of using blocks by Zirkonzahn for more than 4 years, it is considered that these problems can be addressed to some degrees. Accordingly, how to make restorations that are well in harmony with surrounding prosthesis or natural teeth will be discussed.

• Korean Journal of Ichthyology
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• v.20 no.3
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• pp.190-197
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• 2008

Spatio-temporal distribution of eggs and larvae of Japanese anchovy Engraulis japonica in the southern sea of Korea was determined using data obtained from icthyoplanktonic surveys and oceanographic observations between Goheung Peninsula and Goeje Island from May to August 2007. Commercial anchovy catch and size composition from four local fishery cooperative associations were also analyzed in relation to the geographic distribution of eggs and larvae. The abundance of anchovy eggs increased from May to July and was lowest in August. Eggs were mainly distributed between Namhae Island and Goeje Island, where water temperatures were $15{\sim}24^{\circ}C$ and salinities were 32~35‰. In 2007 anchovy landings between Namhae Island and Goeje Island were 11,409 tons at Tongyeong association, 4,137 tons at Masan association, and 2,487 tons at Sacheon association. However, landings between Goheung and Yeosu Peninsula were only 4,411 tons (at Yeosu association). The catch by anchovy tow net was high in the area where eggs were abundantly distributed. This indicates that the distribution of egg density was directly correlated with recruitment of E. japonica. All growth stages were abundant in the study area, indicating that this area is a major spawning and growing ground of E. japonica in Korean waters.

• Journal of Bio-Environment Control
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• v.14 no.1
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• pp.46-51
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• 2005

This experiment was conducted to investigate planting depth, which applied the basic data for planting growth ability and mechanical planting of oriental melon. 'Gumssaragi-eunchun' variety was approach grafting to 'Shintozoa' and seedling was growing during 45 days in the 9cm pot and then planted on Jan. 16. The comparison of planting plots was carried out for four experimental plots, which were separated into 0cm, 4.5cm, 9cm, standard cultivation, and 12cm planting depth in soil. In the tunnel of vinyl house, the lowest and the highest temperature was $9.3^{\circ}C\;and\;41.2^{\circ}C$, respectively, and humidity was $59\~99\%$ during Jan. 18 and 19. The faster graft-take rate after planting was the deeper planting depth. The growth of 40 days after planting was not significant in each planting plot, except 0cm experimental plot. Fruit weight was the heaviest in 4.5cm planting depth of experimental plot but sugar content and flesh thickness were not significant in each planting depth. The more depth in planting meant the more increase in fermented fruit rate and decrease in marketable fruit rate. Marketable yield was 2,361kg per l0a in 9cm planting plot, which was $2\%\;and\;1\%$ lower than in 0cm and 4.5cm, respectively, and $11\%$ greater than in 12cm planting plot.

• Korean Journal Plant Pathology
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• v.3 no.4
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• pp.277-284
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• 1987

Infection rate of the blister rust was investigated with special reference to the effect of eight stand factors at 221 plots selected from 131 Korean pine(Pinus koraiensis S. et Z,) stands, and the data were analyzed by multivariated statistical analysis. Environmental factors such as the density of Pedicularis spp., alternate hosts of the Korean pine blister rust, altitude, stand age, aspect, and pruning treatment, from the highest to the lowest were found to be related to the occurrence of the rust disease, Density of Pedicularis spp, was the most closely related to the' infection rate than any other factors, Especially, Pedicularis spp. growing naturally inside the pine stand had an important effect on the infection rate, but those on the outside more than 100m away had little effects, The higher the elevation, the heavier the infection rate. Infection was the heaviest at the altitudes of above 1,000m with high relative humidity and cool temperature. Infection rate was severe in young stands below 10 years old and had a reducing tendency as they mature. Stands above 16 years old were more resistant. The infection rate by the aspect of stand was higher at E- NE and W -SW exposures than at S-SE and N -NW. The infection rate at non-pruning stands was higher than at pruning stands with the lowest branch being at least 60cm high from the ground.

• Journal of Mushroom
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• v.12 no.2
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• pp.122-126
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• 2014

In analysis of inorganic components of Miscanthus sinensis Andersson var. sinensist, Phosphate increased with the progress of growing stage. in other way potassium, calcium and magnesium was inclined to decrease. The total nitrogen content in the Miscanthus sinensis Andersson var. sinensist was increased until second age cultivated stage, but in its third year, it was decreased apparently. In other way the total carbon content of Miscanthus sinensis was not changed until second year cultivation. But rapid increasing was happen in its third year cultivation stage. 3 year cultivated Miscanthus sinensis Andersson var. sinensist which has a plentiful carbon source can be used as a good culture media source for the formation of mushroom's fruit body. When rice bran added at the amount of 20% to the keep in 65% moisture Miscanthus sinensis Andersson var. sinensist, the fermentation of culture material was well done and the temperature of $50{\sim}55^{\circ}C$ fittest for thermophilic microorganism growth was maintained for 5 days from 5 days after treatment. Rice bran 20% added to the Miscanthus sinensis Andersson var. sinensist was the fittest fermentation culture media for the Pleurotus ostreatus vinyl-bag type cultivation. When Pleurotus ostreatus was cultivated in this culture media, the yield was increased by 60% than whole Miscanthus sinensis Andersson var. sinensist containing culture media. The fermentation Miscanthus sinensis Andersson var. sinensist culture media could be substituted by 20% the sawdust in existing culture media(sawdust 50%+cottonseed bark 30%+cottonseed meal 20%).

• Korean Journal of Organic Agriculture
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• v.27 no.3
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• pp.341-351
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• 2019

Gynura procumbens (Family Asteraceae) is a medicinal plant commonly found in tropical Asia countries such as China, Thailand, Indonesia, Malaysia, and Vietnam. Traditionally, it is widely used in many different countries for the treatment of a wide variety of health ailments such as kidney discomfort, rheumatism, diabetes mellitus, constipation, and hypertension. The objective of this study was to select the natural growth media for hydroponic cultivation of Gynura procumbens. The commercially available thirty four different organic nutrient solutions were analyzed for growing Gynura procumbens. After analysis, two organic nutrient solution were selected, mixed (pH 5.5~6.5 / EC 0.5~1.0 ds/m) and then used as organic fertilizers. Thirty day old seedlings were planted and the environmental conditions of the rhizosphere were also examined to select the natural media composition. The minimum temperature of rhizosphere by type of natural media was highest in cocopeat media and lowest in perlite media. Furthermore, plant growth was examined from 50 days old seedlings, and vermiculite was observed to be most effective and perlite was the least effective component as natural media. The total polyphenol content of the studied plant material was also higher in vermiculite in comparison to other growth media. The Gynura procumbens yields were also higher in vermiculite in comparison to other growth media. Thus, vermiculite can be used to improve Gynura procumbens plant growth as a natural growth media.