• Korean Journal of Materials Research
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• v.30 no.10
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• pp.542-549
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• 2020

Effects of Sc addition on microstructure, electrical conductivity, thermal conductivity and mechanical properties of the as-cast and as-extruded Al-2Zn-1Cu-0.3Mg-xSc (x = 0, 0.25, 0.5 wt%) alloys are investigated. The average grain size of the as-cast Al-2Zn-1Cu-0.3Mg alloy is 2,334 ㎛; however, this value drops to 914 and 529 ㎛ with addition of Sc element at 0.25 wt% and 0.5 wt%, respectively. This grain refinement is due to primary Al₃Sc phase forming during solidification. The as-extruded Al-2Zn-1Cu-0.3Mg alloy has a recrystallization structure consisting of almost equiaxed grains. However, the as-extruded Sc-containing alloys consist of grains that are extremely elongated in the extrusion direction. In addition, it is found that the proportion of low-angle grain boundaries below 15 degree is dominant. This is because the addition of Sc results in the formation of coherent and nano-scale Al₃Sc phases during hot extrusion, inhibiting the process of recrystallization and improving the strength by pinning of dislocations and the formation of subgrain boundaries. The maximum values of the yield and tensile strength are 126 MPa and 215 MPa for the as-extruded Al-2Zn-1Cu-0.3Mg-0.25Sc alloy, respectively. The increase in strength is probably due to the existence of nano-scale Al₃Sc precipitates and dense Al₂Cu phases. Thermal conductivity of the as-cast Al-2Zn-1Cu-0.3Mg-xSc alloy is reduced to 204, 187 and 183 W/MK by additions of elemental Sc of 0, 0.25 and 0.5 wt%, respectively. On the other hand, the thermal conductivity of the as-extruded Al-2Zn-1Cu-0.3Mg-xSc alloy is about 200 W/Mk regardless of the content of Sc. This is because of the formation of coherent Al₃Sc phase, which decreases Sc content and causes extremely high electrical resistivity.

• 한국해양학회지
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• v.24 no.1
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• pp.39-51
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• 1989

A total of 139 surface sediment samples, collected from the continental shelf and slope off the southeastern coast of Korea, were analyzed in order to understand their grain-size, mineral composition and organic carbon content. Based on the grain-size characteristics, five surface sedimentary facies were distinguished: sand, clay, mud, sand-mud mixed, and sand-clay mixed facies. The sand facies appears to be composed mostly of relict sand. For mud, most of which seem to be of recent origin, two different sources were suggested, based principally on their areal distribution pattern and the local hydrographic conditions. Heavy mineral composition of the fine-sand size fraction allowed us to distinguish different sand populations from the study area. On the whole, the Hupo Bank sediments showed a high content of garnet, while the sediments from the northern part of the continental shelf were characterized by a relatively high content of metamorphic minerals (kyanite, sillimanite, andalusite, staurolite). Among clay minerals, the most abundant was illite, with chlorite, kaolinite and smectite following in decreasing order. Organic carbon contents in the sediments of the study area were generally high and showed an average value of 1.94%. The sediment grain-size exerted a strong influence on the organic carbon content. The highest organic carbon content, on the other hand, was found in the continental slope sediments.

• Journal of Animal Science and Technology
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• v.48 no.2
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• pp.227-236
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• 2006

Twenty four Hanwoo steers(average body weight=550.4±42.8kg) were used in the experiment to determine the effects of supplementing coated vitamin C+E with cottonseed on meat quality, meat color and carcass grade in Hanwoo steers fed brewers grain and cracked corn-based fermented feedstuff. Steers were randomly assigned to feeding groups of fermented feedstuff without any supplements(T1) and fermented feedstuff supplemented with coated vitamin C+E and cottonseed(T2). Ether extract content of longissimus dorsi was higher in T2 than in T1(p<0.05). Yellowness and hue-angle among surface colors of longissimus dorsi was lower(p<0.05) in T2 than in T1 but lightness was higher(p<0.05) in T2 than in T1. Ratio of yield grade ‘A’ was higher from T2 group than from T1 group. Marbling score was higher in T2 than in T1(p<0.05). Present results indicate that supplementation of coated vitamin C+E and cottonseed to brewers grain and cracked corn-based fermented feedstuff has positive effects on ether extract content, color, marbling score of longissimus dorsi in Hanwoo steers.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.56 no.2
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• pp.177-181
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• 2011

This research was carried out to establish perfect-drainage time in order to stabilize rice yield and improve rice quality. Treatments of perfect-drainage were conducted 5 days interval during 25 days to 50 days after heading date in the field of Saemangeum Gyehwa, newly reclaimed land. Accumulated temperature after heading date in 2010 increased about $100^{\circ}C$ and precipitation amount decreased a little compared to normal year harvesting time. Average panicle number was 16.5 and spikelet per panicle was 88. Perfect drainage time treatment after 40~50 days was 3% higher in percent ripened grain and 0.6 g heavier in 1,000 grain weight than treatment after 25~35 days. There was no difference of rice yield between perfect drainage time treatment after 25 days and 30~35 days, but rice yield was 7~8% higher in treatment after 40~50 days than 25 days. Head rice ratio in treatment after 35 days was the highest and the sooner perfect drainage time, the lower protein content. Soil moisture negatively correlated with soil hardness and EC in this result. With this results, we proposed that the time of perfect drainage in newly reclaimed land to stable rice production is 40~50 days after heading date.

• Korean Journal of Food Science and Technology
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• v.34 no.5
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• pp.846-855
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• 2002

Several soft white spring and winter wheat cultivars were evaluated by analyzing physicochemical properties such as Single Kernel Characterization System (SKCS), milling properties, Rapid Visco-Analyzer (RVA), mixograph pattern, and sugar-snap cookie-making potentialities. Results of SKCS revealed kernel hardness had a positive correlation coefficient with test weight $(r=0.497^{*})$ and near-infrared reflectance (NIR) hardness $(r=0.495^{*})$. SKCS kernel weight had a significantly high correlation of $r=0.942^{**}$ with SKCS kernel size. The test weight had significantly high correlations with straight-grade flour yield $(r=0.720^{**})$, break flour yield $(r=0.490^{*})$, flour ash content $(r=-0.781^{**})$, and milling score $(r=0.838^{**})$. The average RVA peak viscosity of the soft white winter wheat was higher (195.1 unit) than the soft white winter wheat varieties (135.7 unit). A correlation was found between RVA peak viscosity and swelling volume. Significant correlation coefficients were obtained among cookie properties, milling properties, protein content, and mixograph absorption. The cookie top grain score had a correlation coefficient of $r=0.447^{*}$ with swelling volume.

• Korean journal of food and cookery science
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• v.31 no.5
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• pp.551-556
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• 2015

Iksan370 is a long-spike wheat developed by the Rural Development Administration yielding excellent features components such as cold resistance, disease resistance, and viviparous germination. The physicochemical and material properties of the raw wheat and milled flour of Iksan370 were analyzed to derive its appropriate uses. The raw wheat of Iksan370 showed high contents of ash and proteins at 1.71% and 13.7%, respectively. Its test weight of 763.0 g/L was similar to those of other varieties and its 1,000 kernel weight was high at 45.38 g. The milled flour of Iksan370 had an ash content of 0.45%, which corresponds with a class 1 flour, and its protein content is 12.18%, corresponding with strong flour. The damaged starch was 5.41%, which was lower than that of other varieties. The average grain size was $70.67{\mu}m$ and the grain distribution was at the level of a typical hard wheat. In the farinogram, the water absorption was 58.63%, which corresponded to the level of medium flour. The development time was 7.00 minutes, which was significantly lower than those of Jokyung and Keumkang. The degree of softening was 67.00 BU, similar to those of Yunbaek and Baekjoong. Among the physico-chemical characteristics, the high protein content and typical hard wheat grain distribution of Iksan370 were similar to those of strong wheat, usually used for bread making. However, in the farinogram, the dough development time was short and the degree of softening was high. As a result, Iksan370 was expected to have poor breadmaking properties and a small volume of the final bread product due to insufficient dough durability. On the other hand, Iksan370 showed the highest maximum gelatinization viscosity at 864.00 BU. Therefore, Iksan370 is expected to show glutinous texture when used for noodles and its flour appears to be appropriate for frying powders as well.

• Korean Journal of Breeding Science
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• v.43 no.6
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• pp.538-542
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• 2011

A new malting barley variety, 'Baegho', was developed from a cross between Azuma Golden and Nishinochikara in 1998. An elite line, YMB2139-2B-1-10-2, was selected in 2005 and designated as Milyang137. It showed good agronomic performance in the regional adaptation yield trials (RYT) from 2006 to 2008 and was released with the name of 'Baegho' having high yielding and BaYMV and powdery mildew resistance. The average heading and maturing dates of 'Baegho' were April 21 and May 28, which were 3 and 2 day later than those of Hopum, check variety, at the RYT, respectively. 'Baegho' has shoter culm length (78 cm), more spikes ($1,062per\;m^2$) and heavier 1,000 grain weight (40.7 g) than those of Hopum, respectively. 'Baegho' is resistant to domestic BaYMV strains I, III and IV and powdery mildew at Iksan. In growth habit, 'Baegho' is close to type (IV) that is distinguished from other Korean malting barley cultivars, which could tolerant to premature heading damage that is major concern for the practice of the malting barley cropping. The yield potential of 'Baegho' in the RYT was about 5.57 MT/ha, which is about 13% higher than those of Hopum. This variety has good malting quality in grain and malting analysis showed better 1,000 grain weight, husk rate, diastatic power than those of Hopum. 'Baegho' applied for protection of new varieties of plant in 2009.

• Korean Journal of Breeding Science
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• v.49 no.3
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• pp.250-255
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• 2017

'Hwaweon 7' was developed from a cross between the African upland cultivar, 'Moroberekan' and 'Ilpumbyeo' based on marker-aided backcross selection. The recurrent parent, Ilpumbyeo is a high grain quality cultivar with medium to late maturity. Hwaweon 7 is nearly isogenic to Ilpumbyeo except a small Moroberekan introgressed segment on chromosome 6 harboring genes related with spikelets per panicle and internode diameter. The preliminary and replicated yield trial was conducted at Chungnam National University and Chungcheongnamdo Agricultural Research & Extension (CARES), Yesan in 2010 and 2011. The local adaptability test was carried out by the National Seed Management Office (NSMO) in 2012 and 2013. This cultivar was registered to NSMO with a cultivar designated as "Hwaweon7". This cultivar averaged 80cm in culm length and has a medium growth duration. Milled rice of "Hwaweon7" is translucent and the grain quality traits are comparable to those of the recurrent parent. The average yield potential of Hwaweon 7 in grain was about 6.48 MT/ha at the ordinary fertilizer level for two years about 5.1% higher than that of Ilpumbyeo due to increase in spikelets per panicle. This variety is tolerant to lodging and the tolerance is due to the APO1 gene controlling the base internode diameter on chromosome 6 introgressed from the donor parent, Moroberekan. The Apo1 gene would be useful in enhancing resistance to lodging in rice breeding program.

• Korean Journal of Breeding Science
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• v.49 no.3
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• pp.280-284
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• 2017

'Hwaweon 6' was developed from a cross between 'Hwaseongbyeo' and a wild species, Oryza minuta L. (Acc. No. 101154) based on marker-assisted selection and backcrossing. The recurrent parent 'Hwaseongbyeo' is a high grain quality cultivar with medium maturity. Hwaweon 6 is nearly isogenic to Hwaseongbyeo except a small O. minuta introgressed segment on chromosome 7 harboring genes related with spikelets per panicle. The preliminary and replicated yield trial was conducted at Chungnam National University and Chungcheongnamdo Agricultural Research & Extension (CARES), Yesan in 2009 and 2010. The local adaptability test was carried out by the National Seed Management Office (NSMO) in 2011 and 2012. This cultivar was registered to NSMO with a cultivar designated as Hwaweon 6. This cultivar averaged 80cm in culm length and has a medium growth duration. Milled rice of Hwaweon 6 is translucent and the grain quality traits are comparable to those of the recurrent parent. The average yield potential of Hwaweon 6 in grain was about 6.57 MT/ha at the ordinary fertilizer level for two years about 3.0% higher than that of Hwaseongbyeo due to an introgression of the quantitative trait locus (QTL) for spikelets per panicle (qSPP7) from O. minuta. This variety is comparable to Hwaseongbyeo in low temperature germinability and cold tolerance. The qSPP7 QTL would be useful in enhancing yield potential in rice breeding program.

• Animal Bioscience
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• v.34 no.12
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• pp.1963-1973
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• 2021

Objective: The present study aimed to evaluate the influence of including L-glutamine along with glutamic acid as a supplement in weaned piglets' diets with and without whey powder. Methods: Two assays were carried out. A total of 40 piglets ([Landrace×Large White]×Pietrain) weaned at 24 days of age with an initial body weight of 6.6±0.6 kg were used in the first assay, and the following parameters were evaluated: growth performance, the incidence of diarrhea, morphometry, intestinal integrity, and hepatic glycogen index. The animals were then blocked into four groups according to different diets: diet all-grain feeding (G); diet all-grain feeding with whey powder (GW); and with vs without 1% supplementation of the commercial product containing L-glutamine and glutamic acid (A or NA). Whey powder was added according to the stage of life, corresponding to 17%, 10%, and 5%, respectively, in order to meet the need for lactose. The animals were evaluated at 24 to 42 days and at 24 to 55 days of age. The nutrient digestibility for the second assay was carried out by using 24 animals with an average weight of 11.49±1.6 kg, and the same diets were tested. Results: The supplementation of L-glutamine + glutamic acid or the addition of whey powder in diets for weaned piglets provided (p<0.05) greater feed intake, greater weight gain and improved feed conversion in the initial period (24 to 42 days age). However, in the whole period (24 to 55 days age) only amino acid supplementation affected (p<0.05) growth performance. There was a positive interaction (p<0.05) between the type of diet and L-glutamine + glutamic acid supplementation on villus height, crypt depth and the villus:crypt ratio in the duodenum. In addition, L-glutamine + glutamic acid supplementation reduced (p<0.05) the crypt depth and improved the villus:crypt ratio in the jejunum. The inclusion of whey powder affected (p<0.05) positively the digestibility coefficients analyzed except mineral matter digestibility coeficients. The supplementation of 1% the commercial product composed of L-glutamine and glutamic acid improved (p<0.05) only the digestibility coefficient of crude protein. Conclusion: These results indicate that supplementation of 1% commercial product containing L-glutamine + glutamic acid in diets for piglets from 24 to 55 days of age, dispenses with the use of whey powder when evaluating growth performance. Amino acid supplementation alone or associated with whey powder affects (p<0.05) positively the indicators of the intestinal integrity.