• Korean Chemical Engineering Research
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• v.56 no.6
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• pp.871-877
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• 2018

Storing the surplus energy from renewable energy resource is one of the challenges related to intermittent and fluctuating nature of renewable energy electricity production. $CO_2$ methanation is well known reaction that as a renewable energy storage system. $CO_2$ methanation requires a catalyst to be active at relatively low temperatures ($250-500^{\circ}C$) and selectivity towards methane. In this study, the catalytic performance test was conducted using a pressurized bubbling fluidized bed reactor (Diameter: 0.025 m and Height: 0.35 m) with $Ni/{\gamma}-Al_2O_3$ (Ni70%, and ${\gamma}-Al_2O_3$30%) catalyst. The range of the reaction conditions were $H_2/CO_2$ mole ratio range of 4.0-6.0, temperature of $300-420^{\circ}C$, pressure of 1-9 bar, and gas velocity ($U_0/U_{mf}$) of 1-5. As the $H_2/CO_2$ mole ratio, temperature and pressure increased, $CO_2$ conversion increases at the experimental temperature range. However, $CO_2$ conversion decreases with increasing gas velocity due to poor mixing characteristics in the fluidized bed. The maximum $CO_2$ conversion of 99.6% was obtained with the operating condition as follows; $H_2/CO_2$ ratio of 5, temperature of $400^{\circ}C$, pressure of 9 bar, and $U_0/U_{mf}$ of 1.4-3.

• Journal of Climate Change Research
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• v.2 no.4
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• pp.317-331
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• 2011

The CERES-Barley crop simulation model of DSSAT package was used to assess the impacts of climate change on potential yield of winter covered barley in Korea. 56 sites over the southern part of Korean peninsula were selected to compare the climate change impacts in various climatic conditions. The climatological normals (1971~2000) and the three future climatological normals (2011~2040, 2041~2070, and 2071~2100), based on A1B climate change scenarios of Korea, were used in this study, and the three future climatological normals were simulated under three environmental conditions, where only temperature change, only carbon dioxide change, and both of temperature and carbon dioxide change with future A1B climate change scenarios, respectively. Results: The CERES-Barley model was suitable for predicting climate change impacts on the potential yield of winter covered barley, because of the agreement between observed and simulated outcomes (e.g., the coefficient of determination of grain yield equals 0.84). (1) The only increased temperature effect with the climate change scenarios was mostly negative to the potential yield of winter covered barley and its magnitude ranges from -21% to +1% for the three future normals. (2) The effect of the only elevated carbon dioxide on the potential yield of winter covered barley was positive and its magnitude ranged from 12% to 43% for the three future normals. (3) For increased temperature and elevated carbon dioxide change cases, potential yields increased by 13%, 21%, 19% increase for the 2011~2040, 2041~2070, 2071~2100 normals, respectively.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.64 no.1
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• pp.40-47
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• 2019

This study was conducted to investigate the effect of planting density on plant growth, yield, and quality in the sweet sorghum cultivar 'Chorong' (Sorghum bicolor (L.) Moench). Plants were cultivated at densities of 16.7, 11.1, 8.3, 6.7, and $5.6plants{\cdot}m^{-2}$. Factors related to yield and yield components were analyzed using correlation and multivariate analyses. There was no significant difference among plant densities in stem length from 20 to 110 days after sowing. But the stem diameter was thin, and a decrease in number of tillers occurred more rapidly as planting density increased. At harvest, juice and sugar yield were higher at densities of 16.7 (42.9, $4.16Mg{\cdot}ha^{-1}$, respectively) and 11.1 (37.1, $3.73Mg{\cdot}ha^{-1}$) $plants{\cdot}m^{-2}$ than at 8.3 (30.5, $2.96Mg{\cdot}ha^{-1}$), 6.7 (26.6, $2.41Mg{\cdot}ha^{-1}$), and 5.6 (24.7, $2.22Mg{\cdot}ha^{-1}$) $plants{\cdot}m^{-2}$. The soluble solids and total sugar contents were not different among treatments, but relatively high values were observed at the density of 11.1 and $8.3plants{\cdot}m^{-2}$. As plant density was increased from 5.6 to $11.1plants{\cdot}m^{-2}$, the lodging index (1 = no, 9 = lodging) increased rapidly from 2.00 to 6.33. To determine the optimal planting density, the number of typhoons and topographical characteristics should be considered. Correlation and principal components analyses revealed that plant density exhibited a positive relationship with fresh stem yield ($r=0.62^{**}$), dry stem yield ($r=0.58^{**}$), juice ($r=0.63^{**}$), and sugar yield ($r=0.66^{**}$), but a negative with stem diameter ($r=-0.65^{**}$). The yield factors were not statistically related to stem height, diameter, and number of nodes.

• Analytical Science and Technology
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• v.31 no.6
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• pp.240-246
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• 2018

The present study analyzed standard samples of three types of aluminum matrix certified reference materials (CRM) using GD-MS. Calibration curves were constructed for 13 elements (Mg, Si, Ti, V, Cr, Mn, Fe, Ni, Cu, Zn, Ga, Sn, and Pb), with the slope representing the relative sensitivity factor (RSF). The x- and y-axes of the calibration curve represented ion beam ratio (IBR) and the authenticated value of the standard sample, respectively. In order to evaluate precision and linearity of the calibration curve, RSD and the coefficient of determination were calculated. Curve RSD for every element reflected high precision (within 10 %). For most elements, the coefficient of determination was ${\geq}0.99$, indicating excellent linearity. However, vanadium, nickel, and gallium curves exhibited relatively low linearity (0.90~0.95), likely due to their narrow concentration ranges. Standard RSF was calculated using the slope of the curve generated for three types of CRM. Despite vanadium, nickel, and gallium exhibiting low coefficients of determination, their standard RSF resembled that of the three types of CRM. Therefore, the RSF method may be used for element quantitation. Standard iron matrix samples were analyzed to verify the applicability of the aluminum matrix standard RSF, as well as to calculate the RSD-estimated error of the measured value relative to the actual standard value. Six elements (Al, Si, V, Cr, Mn, and Ni) exhibited an RSD of approximately 30 %, while the RSD of Cu was 77 %. In general, Cu isotopes are subject to interference: $^{63}Cu$ to $^{54}Fe^{2+}-^{36}Ar$ and $^{65}Cu$ to $^{56}Fe-Al^{3+}$ interference. Thus, the influence of these impurities may have contributed to the high RSD value observed for Cu. To reliably identify copper, the resolution should be set at ${\geq}8000$. However, high resolutions are inappropriate for analyzing trace elements, as it lowers ion permeability. In conclusion, quantitation of even relatively low amounts of six elements (Al, Si, V, Cr, Mn, and Ni) is possible using this method.

• Journal of the Korean Society of Marine Environment & Safety
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• v.25 no.4
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• pp.457-467
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• 2019

To investigate the long-term variation characteristics of nutrients in the east coast of Korea, water temperature, salinity, dissolved oxygen, and nutrients were measured at three stations of Sokcho, Jukbyeon and Gampo coasts for five years from 2013 to 2017. For five years, the water temperature of the East Sea coast was in the range of $1.2{\sim}28.8^{\circ}C$, the salinity was in the range of 30.63~34.79 and the dissolved oxygen (DO) was in the range of 3.53~7.64 mL/L. Distribution and variation of the water environment factors in the study area were determined by the vertical stratification of water column and distribution of water temperature. The high DO concentration in Sokcho coast From 2015 to August 2016 is presumed to be the result of the southward inflow of North Korean Cold Water (NKCW). Concentrations of dissolved inorganic nitrogen (DIN, $NH_4-N+NO_2-N+NO_3-N$) ranged $0.11{\sim}24.19{\mu}M$, phosphate concentration ranged $0.01{\sim}1.75{\mu}M$, and silicate ranged $0.17{\sim}32.80{\mu}M$. The N:P ratio was in the range of 0.7~54.3 (mean 15.2) and the N:P slope was in the range of 11.67~13.75. The N:P ratios in this study were lower than the Redfield ratio (16), indicating that nitrate did act as a limiting factor in phytoplankton growth. The correlation ($R^2$) of total N:P ratio was as high as 0.95, indicating that the effect of the surrounding land or non-point sources was not significant. In conclusion, the spatial and temporal variation of nutrients in the east coast of Korea was determined by the vertical mixing of water mass with thermocline and mainly affected by physical factors such as influx of external water masses and coastal upwelling, and the influences from inflows from the land were minimal.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.45 no.3
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• pp.287-297
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• 2019

This study was carried out to evaluate the antioxidant, anti-inflammation, and whitening effect of Hordeum vulgare L. extracts and their fractions. Total polyphenol and flavonoid contents in fractions were varied from 13.58 to 40.06 mg GAE/g and 7.67 ~ 13.67 mg CE/g, respectively. Among the three fractions(chloroform, hexane, and water), $400{\mu}g/mL$ of the chroloform fraction showed similar antioxidant activity to ascorbic acid ($30{\mu}M$) against the 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical. The chloroform and hexane fractions inhibited the NO production of RAW 264.7 cells similar to quercetin ($15{\mu}M$) and the chloroform fraction of $100{\mu}g/mL$ significantly reduced IL-6, iNOS and COX2 gene expression. Additionally, the chloroform fraction inhibited ${\beta}$-hexosaminidase degranulation, IL-4, and IL-13 gene expression in RBL-2H3 cells. All of the fractions inhibited tyrosinase activity in a concentration-dependent manner, and the hexane fraction at $50{\mu}g/mL$ and the chloroform fraction at $100{\mu}g/mL$ significantly inhibited melanin production of B16F10 cells. These results indicated that H. vulgare L. can be used as an effective cosmetic ingredient having anti-inflammation and whitening activity.

• Journal of Mushroom
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• v.17 no.3
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• pp.113-118
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• 2019

Oyster mushrooms are an economically important crop, accounting for 35% of the total mushroom production in Korea. In this study, we developed a new cultivar of Pleurotus ostreatus, known as 'Baekseon,' which is characterized by a white pileus with a white stipe. It was bred by mating monokaryons isolated from white mutant oyster mushrooms that were naturally generated from 'Gonji-7ho' and 'Wonhyeong-1ho' at the Mushroom Research Institute, GARES, Korea in 2018. The optimum temperature for mycelial growth on potato dextrose agar medium was approximately $28-31^{\circ}C$, and the optimum temperatures for primordia formation and growth of fruit bodies on sawdust media were $22^{\circ}C$ and $20^{\circ}C$, respectively. The time required for the bottle-cultured mushrooms to complete spawn running, primordia formation, and growth of fruit bodies was 30 days, 4 days, and 4 days, respectively. The fruit bodies were bundle-shaped, the pilei were round type and white, and the stipes were white. The stipes were slender and longer than those of the control ('Miso'). In the productivity test, the yield per bottle was 185 g/1100 mL, which was 45% greater than that of the control ('Miso'). In the farm test, the yield per bottle for Farm A (Pyeongtaek) and Farm B (Yeoju) was 184 g/1100 mL and 178 g/850 mL, respectively. With regard to the physical properties of fruit bodies, the springiness, cohesiveness, gumminess, and brittleness of stipe tissue were 80%, 57%, 720 g, and 57 kg, respectively. These values were lower than those of the control ('Miso'). To test the shelf life, the fruit bodies were wrapped with antifogging film and stored at $4^{\circ}C$ for 28 days and then at room temperature for 4 days; such conditions were sufficient for maintaining edibility.

• Clean Technology
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• v.25 no.3
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• pp.223-230
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• 2019

This research was performed to evaluate the characteristics of food waste from 5 areas in Gangwon Province, Korea and to predict the $CH_4$ gas production rate. Food wastes were sampled in July and September, 2017. The amount of methane gas generation was evaluated through the biochemical methane potential (BMP) test and a calculation method using chemical composition. Average bulk density and pH of the food wastes were in the range of $0.758{\sim}0.850g\;cm^{-3}$ and 4.29 ~ 4.75, respectively. By physical composition, vegetables were the highest with 56.43 ~ 72.81% with fruits recording 5.31 ~ 8.95%, cereals 1.60 ~ 18.73%, fish and meat 4.47 ~ 12.11%, and filtrate 1.76 ~ 3.64%. The average water content was 69.30 ~ 75.87%, and VS and ash content were 22.50 ~ 27.98% and 1.63 ~ 2.48%, respectively. In addition, $BOD_5$, $COD_{Cr}$, and $COD_{Mn}$ were in the ranges of $17,690.3{\sim}33,154.9mg\;L^{-1}$, $106,212.3{\sim}128,695.5mg\;L^{-1}$, and $51,266.1{\sim}63,426.3mg\;L^{-1}$, respectively. The NaCl content ranged from 0.81 to 1.17%. The results of elemental analysis showed that the contents of C, H, O, N, and S were 44.87 ~ 48.1%, 7.12 ~ 7.57%, 40.13 ~ 43.78%, 3.22 ~ 4.14%, and 0.00 ~ 0.02%, respectively. In a comparison of the methane production yield per VS mass of food waste, there was no significant difference between the cumulative amount (${0.303{\sim}0.354m_{CH4}}^3\;{kg_{VS}}^{-1}$) by the BMP test and the theoretical amount (${0.294{\sim}0.352m_{CH4}}^3\;{kg_{VS}}^{-1}$) calculated by chemical composition.

• Journal of the Korea Organic Resources Recycling Association
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• v.27 no.3
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• pp.49-61
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• 2019

Swine manure has been recognized as a organic sources for composting and many research was conducted to efficiently utilize and treat. This study was to evaluate a feasibility for producing swine manure compost under various treatment with mixture of swine manure and saw dust. Treatments were designed as follows; non aerated composting pile(REF), aerated composting pile of $100L/m^3$(EXP1), and aerated composting pile of $150L/m^3$(EXP2). The total days of fermentation were 28 days and each samples were collected at every 7 days from starting of composting. Temperature sensors were installed under 30~40cm from the surface of composting pile. Inner temperature in composting piles of EXP1 and EXP2 was rapidly increased to $67{\sim}75^{\circ}C$ within 1~2 days. The elevated temperatures found during the thermophilic phase are essential for rapid degradation of organic materials. While swine manure composted, moisture content, total nitrogen, EC of EXP1, EXP2 in sample at 28 days were lower than those of REF. But, pH and organic matter of EXP1, EXP2 in sample at 28 days were higher than those of REF. After finishing fermentation experiment, maturity was evaluated with germination test. Calculated germination index(GI) at REF, EXP1 and EXP2 were 23.49, 68.50 and 51.81, respectively. The values of germination index were higher at EXP1 and EXP2 which is aerated composting piles than REF which is non aerated composting pile. According to the results, composting process by aerated static pile compost had significant effect on the reduction of required period for composting. Supplying adequate amount of air to compost swine manure will greatly reduce composting period.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.4
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• pp.428-434
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• 2019

Many countries have interested animal welfare. Similarly, domestic people have concern for the welfare from companion animals to livestock. Environmental enrichments (EE) are tool to enforce the welfare, however, research with sows is limited. Therefore, this study was investigate to effects of environmental enrichments on performance and behavior properties of gestating sows. A total of 30 pregnant sows (Landrace) were assigned into three treatments that control, T1 (plastic device) and T2 (Rice straw). Period of trial was from Mar. 03. 18. to Mary 19. 18. The EE were allotted to center of experimental pen ($11.6{\times}6.0m$). Body weight (BW), backfat thickness (BF) and cortisol were identified at experimental initial or end date. Behavior was recorded during 24 hours on days 91 of gestation, and then analyzed the patterns. BF was reduced (15.73 vs. 16.56 mm; p>0.05) in T1 than control, but Ending BW, total litter size and alive piglets did not differ. Born dead piglets showed lower tendency (1.00 and 0.63 vs. 1.50 heads; p>0.05) in T1 and T2 than control. Similarly, the enrichments declined farrowing mortality (C, 8.68%; T1, 6.86%; T2, 3.40%; p>0.05). Cortisol was not differed among treatments. In the behavior characteristics, eating showed lower (1.81 vs. 9.68 and 6.99%; p<0.05) in T2 than control and T1. Furthermore, playing or digging were only observed (0.33 and 2.10%; p<0.05) in T1 and T2, respectively, whereas rubbing (0.91%, p<0.05) only showed in the control. These results suggest that the provision of EE would be not negatively affected the performance of the gestating sows and could be led to improvement of the livestock welfare.