• Proceedings of the Optical Society of Korea Conference
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• 2006.07a
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• pp.363-364
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• 2006

We developed 60 GHz analog optical transmitter modules for radio-over-fiber (RoF). They were consisted of an electroabsorption modulator (EAM), impedance matching circuit, and amplifier. The characteristics of fabricated modules were investigated by measuring the signal-to-noise ratio and the noise figure of the 60 GHz RoF link.

• Bulletin of the Korean Chemical Society
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• v.17 no.1
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• pp.43-45
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• 1996

Structural and electronic properties of an alkali metal fulleride, Rb1C60, was studied. In spite of the chain structure with shortdistance between balls along the crystallographic a-direction, the electronic structure calculation study with the X-ray defined crystal structure shows that Rb1C60 is a three-dimensional metal at room temperature. This result is different from the magnetic experiments in which the compound was found to behave as a quasi-one-dimensional metal. Partial Fermi surface nesting is supposed to be the reason for the metal-insulator transition found in Rb1C60 at ∼50 K.

• Bulletin of the Korean Chemical Society
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• v.17 no.9
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• pp.781-786
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• 1996

Mass transport behavior of C60 films on electrodes with different thicknesses has been studied by an Electrochemical Quartz Crystal Microbalance (EQCM) during electrochemical reduction-oxidation processes in the presence of water. C60 films were found to be reduced in the presence of water and they remains quite stable. In thin films, the mass on electrode decreased after a complete cycle while X-ray Photoelectron Spectroscopy (XPS) study does not support the existence or formation of C60-epoxides during electrochemical reduction processes in the presence of water or oxygen.

• Journal of Animal Science and Technology
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• v.51 no.3
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• pp.241-248
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• 2009

Metabolic trial with 3 fistulated sheep was conducted in a 3 $\times$ 3 Latin square design and feeding trial with 24 Hanwoo steers in 12 month of age for 20 months was conducted to investigate the replacing effect of rice straw with fermented spent mushroom (Flammuliua velutipes) compost (FSMC) on fermentation characteristics, ruminal effective degradabilty and whole tract digestibility of nutrients in sheep, and to examine the growth performance of Hanwoo steers. Experimental diets for the metabolic trial with sheep were commercial concentrates and rice straw in the ratio of 70 : 30 (CON, DM basis). Same concentrate with 30% FSMC and 70% rice straw (FSMC-30) and 60% FSMC and 40% rice straw(FSMC-60). Diets for Hanwoo steers in three treatments were same as for metabolic trial in replacing ratio of rice straw with FSMC. pH of rumen fluid in sheep was not affected by FSMC. Ammonia-N content in the rumen fluid was highest in the sheep fed FSMC-60 at 3h (P<0.045). The CON diet increased (P<0.001) acetate proportion at 1h and 3h post feeding compared to FSMC-60 diet while propionate proportion was highest in the sheep fed FSMC-60 diet for all the sampling times (P<0.027~P<0.002). Increased proportion of butyrate was observed at 30 min prior to feeding (P<0.031), and 1h (P<0.011) and 6h(P<0.039) post feeding from sheep fed FSMC-30 diet compared to those from sheep fed other diets. Effective degradability in the rumen was not influenced by experimental diets. Whole tract digestibility of crude protein (P<0.031) and neutral detergent fiber (P<0.006) tended to be increased in the sheep fed CON diet while corresponding values were lowest in the sheep fed FSMC-60 diet. Total body weight gain of Hanwoo steers for 8 months was not different among diets, thus daily body gain was not influenced by the experimental diets.

• Journal of Korean Society of Forest Science
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• v.100 no.4
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• pp.609-615
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• 2011

Forsythia saxatilis is a Korean endemic plant designated as rare and endangered by the Korea Forest Service (KFS). Growth and physiological characteristics of F. saxatilis were investigated under two different light intensities in order to figure out an appropriate growth environment for conservation and restoration of the species in its natural habitat. Shoot length, leaf size and weight, photosynthetic pigment content and photosynthetic parameters were measured for F. saxatilis grown at two experimental plots under relative light intensities (RLI) of 20% and 60% of the full sun, respectively. Fresh leaf weight of plants grown under high relative light intensities (RLI-60) exceeded that of plants grown at 20% RLI. The ratio of fresh leaf weight to leaf size at RLI-60 was 1.47 times superior comparing to that recorded at RLI-20. The content of photosynthetic pigments such as chlorophyll a, b and carotenoid were higher in plants grown at RLI-60, whereas the ratio of total chlorophyll to carotenoid content was higher in the leaves at RLI-20. Photosynthetic rate, stomatal conductance and transpiration rate at RLI-60 were, respectively, 2.5, 2.65 and 1.79 times higher comparing to those recorded at RLI-20. Water use efficiency, however, was higher at RLI-20. The chlorophyll/nitrogen ratio was 1.83 times higher at RLI-20 than at RLI-60. In contrast, the ratio of net photosynthesis to chlorophyll content at RLI-60 was 2.58 times higher than that of RLI-20. In conclusion, light intensity might be the major factor affecting growth and physiological characteristics of F. saxatilis grown under canopy of tall tree species.

• Clean Technology
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• v.12 no.1
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• pp.37-44
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• 2006

The effectiveness of inorganic oxides (DT-30), anionic exchange resin (DT-60) and carbon absorbent (DT-80, DT-90) on the equilibrium and continuous separation characteristics and removal of cobalt, cesium and iodide ion in the waste water was investigated. As a result, DT-30, DT-80 or DT-90, and DT-60 showed excellent separation properties on the cesium, cobalt and iodide respectively. In the equilibrium experiment, the adsorption amount of cesium for DT-30 increased with temperature, but increasd largely with pH. In case of DT-80, adsorption of cobalt was depended on pH but was not influenced by temperature. In the continuous system by passing a heavy metal ion solution through the ion exchange tower, DT-30, DT-90 and DT-60 showed good separation characteristic for cesium, cobalt and iodide respectively. In this case, separation characterization of DT-30 on the cesium and of DT-60 on the iodide were better than that of DT-90 on the cobalt. From the experiment on the effect of impurities on the ion exchange characteristics, impurities such as surfactant and oil did not influence the efficiency of DT-90. In the mean while, ion separation capacity of DT-30 were decreased largely by impurities such as surfactant and oil. Also, surfactant had a strong influence on the effectiveness of DT-60. Accordingly, it turned out to be very important thing that impurities should be removed in the preprocessing stage.

• Food Science and Preservation
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• v.20 no.6
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• pp.894-898
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• 2013

This study was performed to provide the basic data for the prediction of the usefulness of onion with cold tolerance cultivated in Kangwon. The physicochemical properties and antioxidant activity of freeze-dried and hot-air-dried (40 and $60^{\circ}C$) onions were investigated. The moisture content of the raw onion was 90.55%. The crude protein and crude fat contents of the freeze-dried onions were slightly higher than those of the hot-air-dried onions ($40^{\circ}C$ and $60^{\circ}C$). As for the color values, the freeze-dried onion powder was highest in lightness (77.19), and the $60^{\circ}C$ hot air-dried onion was highest in redness (6.09) and yellowness (24.60). Moreover, the color difference (${\Delta}E$) between the freeze-dried and hot-air-dried ($40^{\circ}C$ and $60^{\circ}C$) onion powders was significant. The brown index was lower in the freeze-dried onion than in both hot-air-dried onions. The total phenol content and the 2,2-diphenyl-1-picrylhydrazyl radical (DPPH) scavenging activity of both hot-air-dried onions were higher than those of the freeze-dried onion. These results indicate that the freeze-drying methods protected the physicochemical properties of the onion powder, whereas the hot-air-drying method enhanced the antioxidant activity and the total phenol content of the onion powder.

• Food Science and Preservation
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• v.12 no.6
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• pp.540-545
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• 2005

This study was conducted to evaluate the efficacy of high a)z pre-treatment (60, $100\%$ for 3, 6, 12 hr) on quality of 'Hikawa Hakuho' peach fruits. High a)z treatment inhibited the respiration and ethylene production, especially with long tenn treatment for more than 6 hr. Discoloration of peel, softening and decay were reduced by high $CO_2$ treatment $CO_2$ concentration of $60\~100\%$ did not affect soluble solids content and titratable acidity of fruits. $CO_2$ treated fruits, however, showed higher sweetness score compared with control. As the $CO_2$ concentration and treatment duration increased from 60 to $100\%$ and from 3 to 12 hr, respectively, the efficacy on quality increased. Fruits treated with $100\%\;CO_2$ for 3 hr and $60\%\;CO_2$ for 12 hr, however, showed very low flavor score due to the residual $CO_2$ in flesh. High $CO_2$ injury was not noted at any $CO_2$ levels tested in this study. Above results suggest that $60\%\;CO_2$ treatment for 6 hr resulted in as good control of respiration, ethylene production, decay, discoloration and softening without off-order.

• Journal of the Korean Society of Food Science and Nutrition
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• v.42 no.11
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• pp.1813-1820
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• 2013

This study is conducted to investigate the quality characteristics of cookies containing different levels (0%, 20%, 40%, 60%) of brown rice powder with enhanced levels of GABA (${\gamma}$-amino butyric acid). The pH of cookie dough was higher in cookies containing brown rice powder. A proximate composition analysis showed that the moisture content was increased with the addition of the brown rice powder, yet there was no significant difference in the crude protein and crude fat contents among the added groups. The ash content was the highest in the 60% added group. The spread factor of the control cookie was higher than that of cookies containing 40% and 60% brown rice powder. The incorporation of brown rice powder in cookies lowered the lightness and yellowness values, but increased the redness value. The hardness of the cookies was lower in 40% and 60% added groups than that of the controls. The GABA content in the brown rice added groups was higher than that of the control cookie, and increased as brown rice powder increased. A consumer acceptance test revealed that there was no significant difference in the overall preference scores among the cookies. From these findings, it is suggested that the cookies with brown rice powder up to 60% added can be developed as goods.

• Journal of the Korean Applied Science and Technology
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• v.34 no.3
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• pp.478-486
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• 2017

To find the effect of packaging materials(LDPE $60{\mu}m$, Ceramic $30{\mu}m$ and $60{\mu}m$) to enhance the shelf-life of de-astringent persimmon, the fruits used were the astringent persimmons of "Cheongdobansi" and astringency was removed in $CO_2$. De-astringent persimmon were stored in MA for 140 days at $5^{\circ}C$. During storage, the concentration of oxygen was decreased to 5.2%, while the concentration of carbon dioxide was increased to 5.2% from 18 days. But the concentration of oxygen and carbon dioxide was maintained at a constant concentration until the end of storage. The rate of weight loss was gradually decreases for the storage time elapsed and has better in ceramic $60{\mu}m$ packaging than other packaging materials. Fruit hardness and color value were well maintained in ceramic $60{\mu}m$ packaging. Tannin content and soluble solid were not significant difference among the packaging conditions. Ethanol and acetaldehyde content were decreased during early period of storage and then increased. As a result of objective analysis, de-astringent persimmon storage in ceramic $60{\mu}m$ was more effective than other storage conditions.