• Ocean and Polar Research
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• v.44 no.3
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• pp.261-267
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• 2022

We derived a length-weight relationship for Calanus sinicus off Busan, Korea in spring to estimate the biomass of the C. sinicus population around Korean waters, and compared it with the previously derived equations. The developmental stages and prosome length of C. sinicus used in the relationship ranged from 1,376-1,540 ㎛ for copepodite 4 (CIV), 1,753-1,971 ㎛ for copepodite 5 (CV), and 2,160-2,283 ㎛ for adults (CVI). Dry weight and carbon content were measured from a total of 26 replicates. Length-weight relationships derived in the present study are as follows: log C = 3.342 log PL - 9.449, log DW = 3.394 log PL -9.219, where C is carbon content (㎍), DW is dry weight (㎍), and PL is prosome length (㎛). When comparing the present regression equation of length-weight for C. sinicus with the previous one, our regression equation showed an average carbon estimate to a given range of mean prosome length. The length-weight relationship of C. sinicus in the present study can be used to better estimate the biomass of the C. sinicus population in the coastal waters of Korea.

• Journal of the Korea institute for structural maintenance and inspection
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• v.3 no.4
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• pp.163-171
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• 1999

In this study, we executed fundamental experiment to investigate properties of accelerated carbonation with changing chloride content of concrete used sea sand in order to examine durability. So we obtained the results of following properties of mechanics, durability, concrete with sea sand, determined concrete w/C 30%, 40%, 50%, and fine aggregate 40% and changing containing chloride 0, 0.3, 0.6, $0.9kg/m^3$ by the experiment of accelerated neutralization. The results of this study as follows: 1) As result of changing chloride content of concrete used sea sand augmented in stages $0.3kg/m^3$, accelerated carbonation was increased as increment chloride content. The increment depth was decreased as it went long term age. It was shown the chloride content effected increment of carbonation depth in concrete 2) As a result of changing W/C of concrete used sea sand augmented in stages 10% at a time from 30% to 50%, accelerated carbonation depth of concrete was increased as W/C ratio. 3) As the carbonation concrete used sea sand, compressive strength between 8 weeks and accelerated carbonation depth of 1 weeks, 2 weeks, 4 weeks, 8 weeks was inversion proportion.

• Journal of The Korean Society of Grassland and Forage Science
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• v.32 no.4
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• pp.369-378
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• 2012

This study was performed out to investigate the influence of the mixed application of chemical fertilizer (CF) and liquid swine manure (LSM) on the growth characteristics, dry matter yield, amino acids, minerals, and free sugars in cultivating silage corn on paddy soils. The field experiment was designed in a randomized block design of 3 repetitions with CF 100% treatment (C), CF 70% + LSM 30% treatment (T1), CF 50% + LSM 50% treatment (T2), CF 30% + LSM 70% treatment (T3), and LSM 100% treatment (T4). At this time, the application of LSM was based solely on the nitrogen. Ear length, ear circle, stem diameter, and stem hardness of the silage corn did not show significant differences between treatments. Fresh yield, dry matter yield and TDN yield were highest in T3, whereas the lowest in C treatment (p<0.05). Crude protein, crude fat, and crude ash content were significantly higher in T1, C, and T4 treatment, respectively (p<0.05). However, NDF, ADF and crude fiber content did not show significant difference between treatments. The total mineral content decreased significantly (p<0.05) as the LSM application rate increased. Total composition amino acid content was higher in the order of T1 > T2 > C > T4 > T3 treatment (p<0.05). Free sugar content was higher in the order of T1 > T3 > T4 > T2 > C treatment (p<0.05). Based on the above results, suggests that the mixed application of chemical fertilizer 30~50% and LSM 50~70% (T2 and T3) is the most effective, considering the yield performance and the content of sugar degree and free sugar affecting silage.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2002.07b
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• pp.749-751
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• 2002

$(Pb_{1-x}Sr_x)TiO_3$ $(0.6{\leq}x{\leq}0.8)$ thin films were prepared by the MOD method for tunable microwave device application and their characteristics were investigated as a function of Sr content(x) and applied field. Thin films showed a homogeneous microstructure and the tetragonality(c/a) was slightly decreased with increasing Sr content. With increasing Sr content, Curie temperature of the thin films showed a decreasing tendency. For the PST thin films, the dielectric constant at room temperature, Tc, and $tan{\delta}$ were 750~1900, $-70^{\circ}{\sim}-30^{\circ}C$ and 0.025~0.04, respectively.

• The Korean Journal of Food And Nutrition
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• v.8 no.3
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• pp.206-211
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• 1995

Three kinds of soy sauce were prepared using the brick type of conventional menu(A), the brick type of meju of Aspergillus oryzae (B) and the grain type of menu Aspergillus oryzae (C). Organic acid and fatty acid were analyzed In accordance to aging time of those products Citric acid, lactic acid, acetic acid, malonic acid, butyric acid, oxalic acid, and propionic acid were dejected in all kinds of soy sauce. The content of lactic acid was shown higher than those of any other organic acids. The content of lactic acid was much higher at beginning of preparation and at 180 days in soy sauce B than any other conditions. The content of acetic acid was much higher at beginning of preparation, at 120 days in soy sauce C and at 180 days in soy sauce B than any other conditions. The content of citric acid was highest at beginning preparation in soy sauce C, and that was highest in soy sauce B except beginning preparation to 120 days. Myristic, palmitic, stearic, oleic, linoliic, linolenic, arachidonic acid were detected in all kinds of soy sauce after 180 days. The content of oleic acid were shown 32.59∼53.79% in soy sauce B and in soy sauce C. The content of stearic acid was shown 49.7oA In soy sauce A. Linolinec acid and arachidonic acid were detected in only soy sauce C.

• Korean Journal of Food Science and Technology
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• v.49 no.1
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• pp.97-103
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• 2017

Due to increased consumption and demand for oat-related foods and processed food, this study examined physicochemical properties, antioxidant activity, and ${\beta}-glucan$ contents of 5 Korean naked oat cultivars. Oat seeds had long-grain appearance in all cultivars except for Seonyang. The contents of main components such as protein, starch, and crude fat were significantly different among cultivars. The total ${\beta}-glucan$ content was 3.78-4.60% and the soluble ${\beta}-glucan$ ratio was 71-83%. Fatty acid composition was C18:1, C18:2, C16:0, C18:0, and C18:3. Unsaturated fatty acid (USFA) content was 75.4-81.2%. 2,2-Diphenyl-1-picrylhydrazil (DPPH) and 2,2'-azino-bis-3-ethyl-benzo-thiaxoline-6-sulfonic acid (ABTS) radical scavenging activity were significantly different for each cultivar. Daeyang had the highest ${\beta}-glucan$, USFA content, and antioxidant activity. Protein content showed a negative correlation with starch content (r = -0.775). Antioxidant activity was positively correlated with total phenol content (r =0.760). Ash content and flour whiteness showed a positive correlation (r =0.732).

• Journal of the East Asian Society of Dietary Life
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• v.8 no.4
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• pp.462-468
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• 1998

편이었다. 미량성분으로는 K이 다량으로 존재하였고, 2단계 발효로 제조된 포도식초는 포도양파식초 보다K, Na, Cu함량이 높게 나타났다. ^x Grape vinegar (A) and grape onion vinegar(B) added (3% of onion juice) were produced through two stages of fermentation(alcohol fermentation and acetic acid fermentation) to increase the grape's use. Grape wine which contained 5.6% alcohol was produced on the 3rd day of first stage. Then through the second stages, grape vinegar, of which total acidity was 5.37% was produced. The quality of (A) and ( B) which was produced through the two stages of fermentation was compared with the traditional grape vinegar (C, D) in the market. The content of sugar in (D) was a little higher such as 5.4 $^{\circ}$Brix than others. That of (A) and (B) was 5.13, 4.98 $^{\circ}$Brix respectively. The content of remaining alcohol in (C) was high such as 0.23% comparatively. But there was no remaining alcohol in (A) and (B). The content of acetic acid was 4.3~5.3% as a major organic acid of vinegars. The content of tartaric acid was 340.0 in (A), 315.7 in (B), 322.6 in (C) and 391.7mg% in (D). The content of lactic acid was distinctly high such as 277.4mg% in (D) There were differences such as 9.2~15.5mg% in the content of total free amino acids among grape vinegars. (D) contained 15.5mg% of total free amino acid and (B) also highly such as 12.0mg%. Potassium was high in grape vinegars. The content of potassium, sodium and copper was higher in (A) than (B).

• Journal of the Korean Society of Food Science and Nutrition
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• v.30 no.2
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• pp.292-298
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• 2001

This study was conducted to investigate physicochemical properties of extrudates combining 4 levels of squid (0, 3, 5 and 7%) with 3 levels of defatted soy flour (0, 5, and 10%). Blends were adjusted to moisture content of 27% and then extruded in a single-screw laboratory extruder at 170rpm screw speed and 16$0^{\circ}C$ barrel temperature. The extruded materials were dried at 6$0^{\circ}C$ for 8hr to a moisture content of 3~4% and refrigerated at 4$^{\circ}C$ for 12 hour before examination for textural properties, expansion ratio, bulk density, shear force and Hunter color. Expansion ratio of extrudates decreased as squid content increased whereas bulk density and shear force increased. Expansion ratio of extrudates was not significantly different by defatted soyflour level. Bulk density of products decreased as defatted soyflour content increased but shear force of products increased as defatted soyflour content increased. In scores of sensory hedonic evaluation of snacks, appearance, flavor, texture and overall acceptability values had lowered as squid level increased. Therefore, according to materials contents on extrudates increased, nutritional contents of this products increased and also shear force and bulk density in physical properties increased whereas expansion ratio decreased.

• Corrosion Science and Technology
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• v.5 no.3
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• pp.94-98
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• 2006

The next generation nuclear power reactor will use Pb-Bi as the cooling material. The steel structure materials such as HT-9 used in the reactor suffer from corrosion when they are exposed to high temperature Pb-Bi. Therefore corrosion should be prevented to use Pb-Bi as the coolant material without any safety problem. One method is to control the oxygen content in Pb-Bi. An appropriate amount of oxygen in Pb-Bi can produce a thin oxide layer on steel, and this layer protects the steel from corrosion attack. Since the required oxygen content in Pb-Bi is in the range of $10^{-5}$ to $10^{-7}$ wt%, this small oxygen content can be controlled by flowing a mixture of hydrogen gas and water vapor. The stagnant corrosion test of HT-9 samples was performed by controlling the oxygen content up to 2,000 hours. The corrosion behavior of HT-9 was analyzed at the temperatures of $500^{\circ}C$ and $650^{\circ}C$ with a reduced condition and a oxygen content of $10^{-6}$ wt%.

• Journal of the Korean Ceramic Society
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• v.37 no.4
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• pp.314-319
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• 2000

Microstructueral development and electrical properties in ZnO-Bi2O3-ZnAl2O4 system were investigated with ZnAl2O4 content(0.1~1.0 mol%). The shrinakge of specimens started around $700^{\circ}C$ and finished at 110$0^{\circ}C$, reaching a maximum shrinkage rate at 80$0^{\circ}C$. The shrinkage rate is strongly related to the fromation of a Bi-rich liquid. The increase of the ZnAl2O4 content inhibited the grain growth of ZnO. Most of ZnAl2O4 particles located at the grain boundaries were about 2~3${\mu}{\textrm}{m}$. ZnO grain size changed little up to 110$0^{\circ}C$, but increased markedly above 115$0^{\circ}C$, especially at lower ZnAl2O4 content. Drastic decreasing in breakdown voltage(Vb) with increasing temperature is expected to be dependent on the ZnO grain size and the distribution of the largest grains between the electrode. The nonlinear I-V characteristic was significantly influenced by the ZnAl2O4 content, which exhibited a maximum value at about 15${\mu}{\textrm}{m}$ of ZnO grain size.