• Journal of Korea Foundry Society
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• v.38 no.5
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• pp.103-110
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• 2018

The effects of a heat treatment on the carbide formation behavior and mechanical properties of the cobalt-based superalloy X-45 were investigated here. Coarse primary carbides formed in the interdendritic region in the as-cast specimen, along with the precipitation of fine secondary carbides in the vicinity of the primary carbides. Most of the carbides formed in the interdendritic region were dissolved into the matrix by a solution treatment at $1274^{\circ}C$. Solutionizing at $1150^{\circ}C$ led to the dissolution of some carbides at the grain boundaries, though this also caused the precipitation of fine carbides in the vicinity of coarse primary carbides. A solution treatment followed by an aging treatment at $927^{\circ}C$ led to the precipitation of fine secondary carbides in the interdendritic region. Very fine carbides were precipitated in the dendritic region by an aging heat treatment at $927^{\circ}C$ and $982^{\circ}C$ without a solution treatment. The hardness value of the alloy solutionized at $1150^{\circ}C$ was somewhat higher than that in the as-cast condition; however, various aging treatments did not strongly influence the hardness value. The specimens as-cast and aged at $927^{\circ}C$ showed the highest hardness values, though they were not significantly affected by the aging time. The specimens aged only at $982^{\circ}C$ showed outstanding tensile and creep properties. Thermal exposure at high temperatures for 8000 hours led to the precipitation of carbide at the center of the dendrite region and an improvement of the creep rupture lifetimes.

• Journal of Korean Society for Atmospheric Environment
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• v.10 no.E
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• pp.332-342
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• 1994

Hierarchical cluster and factor analyses were used to identify various influences on free tropospheric air samples at Mauna Loa Observatory in Hawaii during MLOPEX. The cluster analysis separated thirteen chemical and meteorological variables into three characteristic groups (1)clean air, (2)anthropogenically influenced air, (3)marine and volcanic influenced air. The cluster analysis results compared well with those of factor analysis. Six independent components were identified in factor analysis. We have related these components to (1)volcano influenced air, (2)stratosphere-like air, (3)boundary-layer air with recent anthropogenic influence, (4)photochemical haze, (5)marine boundary- layer air, and (6)modified marine tropospheric air. Excluding local influence, we could calculate the nighttime free tropospheric values for $O_3$(41$\pm$10 ppbv), HN $O_3$(94$\pm$45 pptv), N $O_3$$^{[-10]}$ (16$\pm$10 ppbv), S $O_4$$^{[-10]}$ (60$\pm$0 pptv), N $H_4$$^{＋}$(71$\pm$6 pptv), N $a^{＋}$(5$\pm$1 pptv), PAN(13$\pm$9 pptv), MeN $O_3$(3.5$\pm$1.5 pptv), 2-butyl N $O_3$(0.6$\pm$0.1 pptv), $H_2O$$_2$(1015$\pm$44 pptv), $C_2$C $l_4$(3.3$\pm$0.1 pptv), condensation nuclei(249$\pm$13c $m^{-3}$), and dew point(-8.5$\pm$5.3$^{\circ}C$) during this experiment..

• Journal of Korean Society of Environmental Engineers
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• v.30 no.12
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• pp.1287-1293
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• 2008

In this study, a blend of 2-amino-2-methyl-1-propanol (AMP) and ammonia (NH$_3$) was used to achieve high absorption rates for carbon dioxide (CO$_2$) as suggested at several literatures. The absorption rates of aqueous AMP and blended AMP+NH$_3$ solutions with CO$_2$ and nitrogen dioxide (NO$_2$) were measured using a stirred-cell reactor at 303 K. The effect of the added NH$_3$ to enhance absorption characteristics of AMP was studied. The performances were evaluated under various operating conditions. The absorption rates increased following the increase of the concentration of NH$_3$. The absorption rate of NH$_3$ blended into 30 wt.% AMP solution with NO$_2$ at 303 K was 12.6$\sim$32.6% higher than that of aqueous AMP solution without NH3. Also, the addition of 3 wt.% NH$_3$ to 30 wt.% AMP increased 48.2$\sim$41.6% values for the reactions with CO$_2$ and NO$_2$ at 303 K. Therefore, it clearly shows that the reaction rate of AMP with CO$_2$ and NO$_2$ can be increased by the addition of NH$_3$.

• Journal of the Korean Society of Radiology
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• v.10 no.8
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• pp.603-610
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• 2016

This study was performed to analyze the results of radiologic parameters compared both leg weight bearing position to single leg weight bearing position in ankle osteoarthritis. Between January 2016 and June 2016, 25 patients (50 ankles) who visited our Hospital to treat ankle pain. In radiographic assessment, We masured tibial anterior surface angle(TAS), tibial medial malleolar angle(TMM), talar tilting angle(TT), joint space width(JSW), tibiotalar joint space, fibulotalar joint space of ankle as radiologic parameters. On the right leg of the both leg weight bearing position, TAS was $87.24^{\circ}$, TT was $6.44^{\circ}$, TMM was $26.76^{\circ}$, fibulotalar joint space was 0.98mm. Right leg of the single leg weight bearing position, TAS was $88.93^{\circ}$, TT was $2.41^{\circ}$, TMM was $19.77^{\circ}$, fibulotalar joint space was 1.6mm. And then, on the left leg of the both leg weight bearing position, TAS was $87.25^{\circ}$, TT was $5.71^{\circ}$, TMM was $23.92^{\circ}$, fibulotalar joint space was 1.22 mm and left leg of the single weight bearing position, TAS was 88.75, TT was $3.19^{\circ}$, TMM $21.45^{\circ}$, fibulotalar joint space was 1.22 mm. There are unsimilarity between measure values of TAS and tibiotalar joint space. As the result of test of weight bearing ankle study, it would be more exact to examine to measure one side in the first time rather than both to conclude on accurate measurement.

• Journal of the Korean Vacuum Society
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• v.21 no.6
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• pp.333-341
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• 2012

Indium Tin Oxide (ITO) thin films were prepared by RF magnetron sputtering with different flow rates of $O_2$ gas from 0 to 12 sccm. Electrical and optical properties of these films were characterized and analyzed. ITO deposited on soda lime glass and RF power was 2 kW, frequency was 13.56 MHz, and working pressure was $1.0{\times}10^{-3}$ Torr, Ar gas was fixed at 1,000 sccm. The transmittance was measured at 300~1,100 nm ranges by using Photovoltaic analysis system. Electrical properties were measured by Hall measurement system. ITO thin films surface were measured by Scanning electron microscope. Atomic force microscope surface roughness scan for ITO thin films. ITO thin films secondary electron emission coefficient(${\gamma}$) was measured by ${\gamma}$-Focused ion beam. The resistivity is about $2.4{\times}10^{-4}{\Omega}{\cdot}cm$ and the weighted average transmittance is about 84.93% at 3 sccm oxygen flow rate. Also, we investigated Work-function of ITO thin films by using Auger neutralization mechanism according to secondary electron emission coefficient(${\gamma}$) values. We confirmed secondary electron emission peak at 3 sccm oxygen flow rate.

• Food Science and Preservation
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• v.21 no.4
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• pp.483-490
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• 2014

This study was conducted to evaluate the quality and to inhibit the lipid oxidation of Yackwa with 0, 1, 2, or 3% mulberry concentrate added. We stored Yackwa at $60^{\circ}C$ for three weeks. After the three-week storage, the acid value of the Yackwa with mulberry concentrate was lower than that of the control Yackwa. The hydroperoxide value (22.39 meq/kg) of the Yackwa with 3% mulberry concentrate at two weeks of storage was 50% lower than that of the control Yackwa (47.03 meq/kg). Also, after three-week storage, the TBA value of the Yackwa with 3% mulberry concentrate was about two times lower than that of the control group. The L and b values in the Hunter color system of the Yackwa with mulberry concentrate decreased significantly as the amount of the mulberry added increased, whereas the a value increased. The antioxidant activity, such as the DPPH radical scavenging activity, significantly increased in the Yackwa with mulberry concentrate, unlike in the control. These results might have been caused by the mulberry concentrate, which contains an antioxidant. The ability of the mulberry concentrate to delay the rancidity of the Yackwa was due to its antioxidant activity.

• Food Science and Preservation
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• v.22 no.5
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• pp.674-682
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• 2015

In this study, vinegar was produced using urushiol-free fermented Rhus verniciflua extract to create a lacquer with added value. The effect of manufacturing conditions on the quality of vinegar using detoxified R. verniciflua extract for fermentation was investigated. The acidity of the vinegar for inoculations with various liquid starter contents was 4.8~4.9%, and it was similar among all treatment groups. The acidity of vinegar was higher when the initial alcohol content was high. The acetic acid yields were 82.8%, 84.4%, 77.7%, and 69.5%, and the maximum yield was observed when the initial alcohol content was 6%. For acetic acid fermentation using different amounts of detoxified R. verniciflua extracts, the acidity of the vinegar with the extract after fermentation was 5.3~5.9%. However, the acidity of vinegar without the extract was 5.5%. The intensity of the brown color was high for vinegar without the extract. Hunter's L values were high for vinegar with an extract content of 2%. Acetic acid (53.3~65.8 mg/mL) was the predominant acid. Arginine ($190.3{\sim}333.3{\mu}g/mL$), proline ($125.6{\sim}290.8{\mu}g/mL$), alanine ($126.1{\sim}270.9{\mu}g/mL$), and glutamic acid ($159.0{\sim}262.4{\mu}g/mL$) were the predominant amino acids in detoxified R. verniciflua vinegar.

• Journal of the Korean Society of Food Science and Nutrition
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• v.42 no.9
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• pp.1439-1445
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• 2013

The aim of this study was to investigate the quality characteristics of rice cookies specifically prepared with rice flour following enzyme treatment. In this study, three types of specific enzyme treatments, that is, ${\alpha}$-amylase, ${\beta}$-amylase, and cellulose+${\beta}$-glucanase were applied on the effect of rice flour with respect to desired quality characteristics of the rice cookies. Based on our study results, we have found that the density of dough in the rice cookies was not significantly different between that of the non-enzyme treated (control) and the enzyme treated group. However, we found that the spread factor of rice cookies, prepared with rice flour treated with ${\beta}$-amylase, was higher than that of the control. It was also found that the moisture content of rice cookies (with added enzyme-treated rice flour) was 3.20 to 3.90%; however, this range is much lower than that observed in the control. Further, we observed that Hunter color's L-values were significantly higher for the control than those of the enzyme-treated cookies. We also found that hardness of enzyme-treated cookies was comparatively better than that of the control. In addition, the sensory acceptability scores of the enzyme-treated cookies were found to be significantly higher than the control in decisive parameters such as aroma, appearance, flavor, taste, texture, and overall acceptability. Based on our findings, we suggest that ${\alpha}$-amylase treated rice flour is an effective ingredient for improving the overall quality of rice cookies.

• Korean Journal of Food Science and Technology
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• v.42 no.6
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• pp.721-726
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• 2010

The objective of this study was to evaluate several varieties of aseptic-packaged cooked rice including Juanbyeo. Quality evaluations, such as by amylose, setback, toyo values and amylograms, were significantly higher in the Juanbyeo as compared to other samples. In addition, the Juanbyeo aseptic-packeged cooked rice showed significantly higher palatability characteristics and had a greater water absorption ratio than the other samples. For cold cooked rice, the relationship between palatability and texture was significantly high (p<0.01). Ilpumbyeo showed high scores for taste as a hot cooked rice, but as a cold cooked rice taste scores were lower than other samples. In the case of Juanbyeo cold cooked rice flavor was improved. When the Juanbyeo aseptic-packaged cooked rice was reheated in a microwave oven, it had better palatability than other varieties. Thus, the results of this study suggested that Juanbyeo can be effectively utilized as aseptic-packaged cooked rice.

• Journal of the Korean Society of Radiology
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• v.8 no.4
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• pp.211-216
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• 2014

Radium is rock or soil of crust or uranium of building materials after radioactivity collapse process are created colorless and odorless inert gas that accrue well in sealed space like basement. It inflow to lung circulate respiratory organ and caused lung cancer because of deposition of lung or bronchial tubes. In this study, the air in the elementary school classroom nongdoeul tonkatsu place of measured values were compared using the calculated annual internal radiation exposure. La tonkatsu exposure measured in primary school classroom at least five schools when you close the windows in the average floor 0.56mSv 2 floors ground floor windows when opened 0.384mSv 048mSv 3 floors, 2 floor levels of the same three layers 0.31mSv 0.296mSv the human exposure to radon and radiation on the first floor of 3 floors above ground in a lot of exposure was moderate. When you close the window from the first floor up 0.384mSv 056mSv 3 floors with a minimum annual radiation exposure due to natural radiation in the 16 to 23.3 percent minimum 2.4mSv accounted for. When I opened the window to the maximum annual radiation exposure 2.4mSv 0.296mSv 0.31mSv least a minimum of 12.3 to 12.91% accounted for Results suggest that more than five chodeunghakgyoeun La tonkatsu domestic radon measurements conducted below regulatory requirements and internal exposure has also fall within the normal range. People The less the radiation exposure to the human body because it reduces the impact in the classroom in elementary school vent windows often reduced to the maximum radon concentration in the air, if called tonkatsu be able to reduce radiation exposure for the immune system is weak and elementary will be helpful to experiment more in the future for the school authorities called tonkatsu investigation is done to him if the action to establish a more secure school building facilities is thought would be helpful.