• Applied Chemistry for Engineering
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• v.3 no.3
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• pp.527-534
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• 1992

Raney nickel was used as catalyst in the hydrogen electrode for an alkaline fuel cell. The hydrogen electrode manufactured with the Raney nickel catalyst which was sintered at $700^{\circ}C$ was found to have the highest electrode performance. Using the Raney nickel powder of average particle size $90{\AA}$ for the electrode, the current density which had been measured was $450mA/cm^2$ at $80^{\circ}C$ using 6N KOH solution as an electrolyte. The effects of PTFE addition were investigated with CO-chemisorption, polarization curves and Tafel slope. CO-chemisorption had shown the optimum value when the Raney nickel was mixed with 5wt% of PTFE, but from the current density and Tafel slope at porous Raney nickel electrode, the appropriate value of PTFE addition was 10wt%. Recommendable Ni and Al portion for Raney nickel was 60 : 40 and loading amount was $0.25g/cm^2$. Also the influence of pressing pressure for manufacturing catalytic layer and for junction with gas diffusion layer was examined. The morphology of catalyst surface was investigated with SEM. The influence of reactivation time and heat-treatment temperature were also studied.

• Horticultural Science & Technology
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• v.33 no.5
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• pp.784-788
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• 2015

A new cultivar 'Picnic' originated from an artificial cross between 'Fuji' and 'Sansa' at National Institute of Horticultural & Herbal Science in 1994. The cultivar was preliminarily selected among the elite siblings for its high fruit quality in 2003. After regional adaptability tests in five districts for four subsequent years as 'Wonkyo Ga-34', it was ultimately selected in 2008. Optimum harvest time is late September. Mature fruit has mean weight of 233 g and is conic with light red skin on a greenish yellow ground and yellowish white flesh. The fruit contains a favorable total soluble solids content at $13.8^{\circ}Brix$ and titratable acidity at 0.43%, which results in gustatory harmony between sugars and acids. It is not resistant to bitter rot or Marssonina blotch. 'Picnic' exhibits a physiological cross compatibility with leading cultivars such as 'Fuji', 'Hongro' and 'Tsugaru'. Tree topology is semi-spreading with a weak growth habit.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.9
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• pp.322-328
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• 2016

This study investigated the effects of temperature, salinity, and algal diet to find the optimal conditions for 5 days for the mass culture of the tropical tintinnid, Metacylis tropica. This tintinnid had a small, hyaline, and ovoid lorica. The oral diameter, length, and maximum width of the lorica were $36.7{\mu}m$, $49.5{\mu}m$, and $44.5{\mu}m$, respectively. In the temperature experiments, the highest maximum density and population growth rate were observed at $30^{\circ}C$ with 340.7 cells/mL and 1.1/day, respectively. Lower salinities adversely affected the population growth of M. tropica. The maximum density was observed at 33 ppt (840 cells/mL). In the diet experiments, M. tropica fed Isochrysis galbana showed the highest density (413 cells/mL) and population growth rate (1.2/day). As a result, M. tropica is appropriate as a potential prey organism for early fish larvae with smaller mouths because the tintinnid has a relatively small size compared to the rotifer. In addition, the conditions of $30^{\circ}C$, 33 ppt and supplying I. galbana would be effective in the cultivation of M. tropica.

• Journal of Chitin and Chitosan
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• v.23 no.4
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• pp.285-292
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• 2018

In this study, for the purpose of decomposing food waste, the strain was screened from traditional fermented food and soils. The enzyme activity (protease, amylase, cellulase, lipase) experiment was carried out using the paper disc method in 212 strains isolated from 5% NaCl media. Among them, only the strains having enzyme activity of more than 2 (soil) or more than 4 (traditional fermented food) with the halozone of enzyme activity of 15 mm or more were selected first, and microorganism identification through 16S rRNA sequencing was performed. Finally, were identified such as Bacillus subtilis, Bacillus amyloliquefaciens, Bacillus siamensis, Bacillus licheniformis, Bacillus aquimaris, Bacillus megaterium, Bacillus koreensis, Bacillus stratoshericus, Bacillus aryabhattai, Bacillus safensis, Marinobacter hydrocarbonoclasticus. 11 species of mixed strains were confirmed that the culture time was 24 hours, the incubation temperature was $30^{\circ}C$ and the optimum pH was 7.0. In order to confirm the degree of decomposition of standard food wastes (100 g) by treating 11 kinds of mixed strains (25%), solid content of more than $2000{\mu}m$ was determined to be 103 g for the sterilized water group and 18 g for the mixed strains group. And the rest was decomposed to a size of less than $2000{\mu}m$.

• Korean Journal of Breeding Science
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• v.41 no.3
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• pp.354-357
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• 2009

"Wonkyo Na-heukseong 2" was selected from a cross between "Kiyomaro", late season European cultivar with highly resistance and "Mansoo", late season Asian cultivar with long storability, large size and low susceptibility to pear scab made in 1997 at the National Institute of Horticultural & Herbal Science of Rural Development Administration in Korea. "Kiyomaro", released cross between "Taiheiyo" and "Bartlett" with scab resistance caused by Venturia nashicola in Japan, with no visual symptoms on any leaves was used as scab resistant source after field investigation and artificial inoculation test during 1997~1999. "Wonkyo Na-heukseong 2" blooms 1 day earlier than "Mansoo" and 3 days later than "Kiyomaro" in 2008. It is strong in tree vigor and upright-spreading in tree habit. It is classified as highly resistant to pear scab as "Kiyomaro" and "Bartlett", and cross-compatible with parental variety and Korean major pear varieties such as "Niitaka" and "Wonwhang". The average optimum harvest time of "Wonkyo Na-heukseong 2" was approximately 180 days after full bloom and it matured about 20 days shorter than parental varieties. The fruit is spindle in shape and yellowish greenish brown in skin color. Average fruit weight was 484 g and soluble solids content was $13.2^{\circ}Brix$. The flesh had medium to high juice and negligible grit. Its fruit was crisp like Asian pear.

• Journal of the Korean Society of Propulsion Engineers
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• v.19 no.3
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• pp.83-88
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• 2015

Coating materials used in the electron beam (EB) deposition method, which is being studied as one of the fabrication methods of thermal barrier coating, are exposed to high power electron beam at focused area during the EB deposition. Therefore the coating source for EB process is needed to form as ingot with appropriate density and microstructure to sustain their shape and stable melts status during EB deposition. In this study, we tried to find the optimum powder condition for fabrication of ingot of 8 wt% yttria stabilized zirconia which can be used for EB irradiation. It seems that the ingot, which is fabricated through bi-modal type initial powder mixture which consists of tens of micro and nano size particles, was shown better performance than the ingot which is fabricated using monolithic nanoscale powder when exposed to high power EB.

• Asian Journal of Turfgrass Science
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• v.23 no.2
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• pp.271-278
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• 2009

This study was conducted to investigate the effect of the mixture ratio of the inorganic soil amendments on the soil physicochemical properties. In this experiment, three kinds of soil amendments which had similar pH, EC and particle size, the A, B and C, were tested. The mixture ratio of soil amendment were 0%, 3%, 5%, 7% and 10% (V/V) incorporated with sand which met to the USGA(United State of Golf Association) particle standard. To analyze the effects of amendment on chemical soil properties, pH, EC(electrical conductivity) and CEC(cation exchangeable capacity) were measured. The porosity, bulk density and hydraulic conductivity also measured to analyze the changes of physical properties. In the chemical properties, pH was significantly related to the mixture ratios of amendments, A and C(P<0.05), CEC and EC also related to the ratios of C(P<0.01). When the results were applied to the USGA standard of the soil physical properties, the optimum mixture ratios of each amendment were 3% in A and B, and 7~10% in C. To analyze the corelation of mixture ratio versus to physical character, volume of porosity was significantly related to the ratio of B (P<0.05), and showed similar corelation in porosity and hydraulic conductivity with ratio of C(P<0.05). These results indicate that types and mixture ratio of inorganic soil amendments should affect on soil physio-chemical properties of root zone on USGA sand green.

• Food Science and Preservation
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• v.18 no.3
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• pp.414-422
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• 2011

The optimum condition for phenolics contents extraction from purple sweet potato was 12 hrs. in 50% ethanol. The electron donating scavenging activities (DPPH), ABTS radical cation decolorization (ABTS) and antioxidant protection factor (PF) of Jami, Yeonjami and Shinjami were higher than general sweet potato, and thiobarbituric acid reaction substance (TBARs) was below 30%. The minimum inhibitory concentration (MIC) against Staphylococcus aureus and Escherichia coli on skin were each 5,000 and 2,500 ppm in all purple sweet potatoes, and MIC of Jami was the lowest as 2,500 ppm against Staphlococcus epidermidis. The whitening (tyrosinase inhibitory) activity of purple sweet potatoes was the highest as 62.5% and 48.7% in Jami water and ethanol extracts. The anti-inflammation (hyaluronidase inhibitory) activity of purple sweet potatoes was the highest as 25.3% and 94.4% in Jami water and ethanol extracts. The safety of cosmetic with Jam; extracts was assessed by various safety profiles. pH and viscosity change of essence for 90 days was not detected. Cosmetic was stable to temperature and light for 90 days. The result to measure changes of skin color and pore size of the skin was that an aged skin was more effective than young skin.

• Korean Chemical Engineering Research
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• v.57 no.4
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• pp.512-518
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• 2019

To develop a membrane electrode assembly (MEA) with lower Pt loading and higher performance in proton exchange membrane fuel cells (PEMFCs), it is an important research issue to understand interfacial structure of Pt/C catalyst and ionomer and design the catalyst layer structure. In this study, we prepared short-side-chain Nafion-based ionomer dispersion using propylene glycol (PG) as a solvent instead of water which is commonly used as a solvent for commercially available ionomers. Cathode catalyst layers with different ionomer content from 20 to 35 wt% were prepared using the ionomer dispersion for the fabrication of four different MEAs, and their fuel cell performance was evaluated. As the ionomer content increased to 35 wt%, the performance of the prepared MEAs increased proportionally, unlike the commercially available water-based ionomer, which exhibited an optimum at about 25 wt%. Small size micelles and slow evaporation of PG in the ionomer dispersion were effective in proton transfer by inducing the formation of a uniformly structured catalyst layer, but the low oxygen permeability problem of the PG-based ionomer film should be resolved to improve the MEA performance.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.38 no.6
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• pp.859-865
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• 2018

A construction of infrastructures and base station on the moon could be undertaken by linking with the regions where construction materials and energy could be supplied on site. It is necessary to detect craters on the lunar surface and gather their topological information in advance, which forms permanent shaded regions (PSR) in which rich ice deposits might be available. In this study, an effective method for automatic detection of lunar craters on the moon surface is taken into consideration by employing a latest version of deep-learning algorithm. A training of a deep-learning algorithm is performed by involving the still images of 90000 taken from the LRO orbiter on operation by NASA and the label data involving position and size of partly craters shown in each image. the Faster RCNN algorithm, which is a latest version of deep-learning algorithms, is applied for a deep-learning training. The trained deep-learning code was used for automatic detection of craters which had not been trained. As results, it is shown that a lot of erroneous information for crater's positions and sizes labelled by NASA has been automatically revised and many other craters not labelled has been detected. Therefore, it could be possible to automatically produce regional maps of crater density and topological information on the moon which could be changed through time and should be highly valuable in engineering consideration for lunar construction.