• Korean Journal of Agricultural Science
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• v.46 no.2
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• pp.315-322
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• 2019

In this study, the contents of ${\beta}$-carotene and cholesterol were evaluated in various types of agricultural and processed foods (vegetables, legume products, dairy products, and eggs). Certified reference material (CRM) with an assigned value was used for the validation of the ${\beta}$-carotene and cholesterol analytical methods. High recoveries (accuracy) of ${\beta}$-carotene (96%) and cholesterol (97%) were obtained from the quantitative analysis of the CRM, with a relative standard deviation (%) of 1.86 and 3.35% for the ${\beta}$-carotene and cholesterol, respectively. Vegetables contained relatively high concentrations of ${\beta}$-carotene (raw Toona sinensis, $1650.97{\mu}g/100g$, a raw small onion, $879.09{\mu}g/100g$, and a raw lettuce stem, $591.89{\mu}g/100g$). The ${\beta}$-carotene values in dried chickpeas ($22.94{\mu}g/100g$) and dried brown lentils ($21.98{\mu}g/100g$) were similar. The highest ${\beta}$-carotene value among the analyzed dairy products was found in banana milk ($234.21{\mu}g/100g$) while other flavored products (strawberry milk and chocolate milk) did not contain any ${\beta}$-carotene. Furthermore, ${\beta}$-carotene was not detected in goat milk and high calcium milk in this study. With regard to cholesterol among the analyzed samples, the highest cholesterol value was found in egg yolk (629.30 mg/100 g), and cooking methods (boiling and frying) had little effect on the cholesterol levels of eggs. In addition, the cholesterol content in vanilla ice cream was 28.77 mg/100 g which was the highest value among the analyzed dairy products.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.54 no.5
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• pp.742-750
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• 2021

Ixeris repens is a type of halophyte that grows in high salinity sands found in coastal sand dunes and sandy shores. This study was conducted to investigate the contents, antioxidant potency, and physiological activities of I. repens. In analyses of general composition, carbohydrate, protein, ash, and moisture content were 57.42%, 10.48%, 11.99% and 10.29%, respectively. Potassium, calcium, sodium, and magnesium were its most prevalent minerals. The solvents used to extract I. repens were 70% ethanol, 80% methanol, and distilled water. Among the resultant extracts, ethanol and methanol extracts displayed higher total polyphenol and flavonoid contents than the water extract. ABTS (IC50, 0.12 mg/mL) and FRAP (0.77 mM) radical scavenging activity were highest in the water extract, while methanol extract exhibited the strongest DPPH radical scavenging activity (IC50, 1.32 mg/mL), NO scavenging activity (IC50, 4.10 mg/mL), and reducing power (EC50, 0.14 mg/mL). Tyrosinase, elastase, and α-glucosidase inhibitory activities were highest in the ethanol extract. The ethanol extract also possessed the most potent acetylcholinesterase inhibitory activity. These results indicate that I. repens may be useful as an antioxidant, and a functional substance in food and pharmaceutical materials.

• Journal of Powder Materials
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• v.28 no.1
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• pp.31-37
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• 2021

This study explores reducing the oxygen content of a commercial Ti-48Al-2Cr-2Nb powder to less than 400 ppm by deoxidation in the solid state (DOSS) using Ca vapor, and investigates the effect of Ca vapor on the surface chemical state. As the deoxidation temperature increases, the oxygen concentration of the Ti-48Al-2Cr-2Nb powder decreases, achieving a low value of 745 ppm at 1100℃. When the deoxidation time is increased to 2 h, the oxygen concentration decreases to 320ppm at 1100℃, and the oxygen reduction rate is approximately 78% compared to that of the raw material. The deoxidized Ti-48Al-2Cr-2nb powder maintains a spherical shape, but the surface shape changes slightly owing to the reaction of Ca and Al. The oxidation state of Ti and Al on the surface of the Ti-48Al-2Cr-2Nb powder corresponds to a mixture of TiO2 and Al2O3. As a result, the peaks of metallic Ti and Ti suboxide intensify as TiO2 and Al2O3 in the surface oxide layer are reduced by Ca vapor deposition.

• Journal of Powder Materials
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• v.27 no.6
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• pp.498-502
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• 2020

We investigate the effects of Yb2O3 and calcium aluminosilicate (CAS) glass as sintering additives on the sintering behavior of AlN. The AlN specimens are sintered at temperatures between 1700℃ and 1900℃ for 2 h in a nitrogen atmosphere. When the Yb2O3 content is low (within 3 wt.%), an isolated shape of secondary phase is observed at the AlN grain boundary. In contrast, when 3 wt.% Yb2O3 and 1 wt.% CAS glass are added, a continuous secondary phase is formed at the AlN grain boundary. The thermal conductivity decreases when the CAS glass is added, but the sintering density does not decrease. In particular, when 10 wt.% Yb2O3 and 1 wt.% CAS glass are added to AlN, the flexural strength is the highest, at 463 MPa. These results are considered to be influenced by changes in the microstructure of the secondary phase of AlN.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.55 no.3
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• pp.249-256
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• 2022

This study was conducted to investigate the sensory and nutritional properties of oyster Crassostrea gigas gratin with cream sauce (OG-CS) and to compare with commercial seafood gratin with cheese (control). The proximate composition (%, w/w) of OG-CS was 61.8 of moisture, 8.5 of protein, 16.1 of lipid, 1.2 of ash, 12.4 of carbohydrate, of which the moisture was lower and protein, lipid, ash, and carbohydrate values were higher than those of the control. Based on the results of sensory evaluation by panel members, OG-CS was superior to the control for all parameters, including taste, flavor, texture, nutrition, and overall acceptance. The total amino acid content of OG-CS (7.33 g/100 g) was higher than that of the control (5.20 g/100 g). The major amino acids of OG-CS were glutamic acid (18.8%), proline (9.8%), and leucine (8.2%). The mineral levels of OG-CS were 134.5 mg/100 g for calcium, 164.9 mg/100 g for potassium, 0.8 mg/100 g for iron, and 4.5 mg/100 g for zinc, which were all higher than those of the control. The major fatty acids of OG-CS were 12:0 (28.2%), 16:0 (24.9%), and 14:0 (13.6%), which were the same as those in the control.

• Journal of The Korean Society of Grassland and Forage Science
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• v.42 no.3
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• pp.162-168
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• 2022

This study was carried out to investigate the effects of planting densities on the growth characteristics, dry matter yield, and feed value of "Geukdong 6" (a new variety of corn for feed). The experimental design was arranged in a randomized block design with three replications. Treatments consisted of six planting densities, 60 cm × 25 cm (T1), 60 cm × 30 cm (T2), 70 cm × 25 cm (T3), 70 cm × 30 cm (T4), 80 cm × 25 cm (T5) and 80 cm × 30 cm (T6). All treatments were sown on May 14, 2021, and the harvest was on October 3 (late flowering). Plant length and the number of tillers were the highest in T5 (p<0.05), but the number of leaves and stem diameter were the highest in T6 than in the other treatments (p<0.05). Leaf length, leaf width, and dead leaf were not significantly different among the treatments. Organic matter was highest in T6, and crude protein was highest in T5 (p<0.05). The ether extract was not significantly different among the treatments. Crude fiber, NDF, and ADF were highest in T2 with relatively higher planting density (p<0.05). Calcium and phosphorus were not significantly different among the treatments. TDN content was the highest in T3 (p<0.05). Sugar degree (Brix), fructose, glucose, dextran, isomerose, and inverted sugar were not significantly different among the treatment. Fresh yield, dry matter yield and TDN yield were higher in order of T6 > T5 > T4 > T3 > T2 > T1 (p<0.05). Relatively feed value was higher in order of T3 > T6 > T5 > T1 > T4 > T2 (p<0.05). Based on the above results, planting density could be recommended from 80 cm × 30 cm for efficient production of "Geukdong 6".

• Advances in concrete construction
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• v.12 no.6
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• pp.479-490
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• 2021

Present research is mainly focused on, microstructural and durability analysis of Graphene Oxide (GO) in Wollastonite (WO) induced cement mortar with silica fume. The study was conducted by evaluating the mechanical properties (compressive and flexural strength), durability properties (water absorption, sorptivity and sulphate resistance) and microstructural analysis by SEM. Cement mortar mix prepared by replacing 10% ordinary portland cement with SF was considered as the control mix. Wollastonite replacement level varied from 0 to 20% by weight of cement. The optimum replacement of wollastonite was found to be 15% and this was followed by four sets of mortar specimens with varying substitution levels of cementitious material with GO at dosage rates of 0.1%, 0.2%, 0.3% and 0.4% by weight. The results indicated that the addition of up to 15%WO and 0.3% GO improves the hydration process and increase the compressive strength and flexural strength of the mortar due to the pore volume reduction, thereby strengthening the mortar mix. The resistance to water penetration and sulphate attack of mortar mixes were generally improved with the dosage of GO in presence of 15% Wollastonite and 10% silica fume content in the mortar mix. Furthermore, FE-SEM test results showed that the WO influences the lattice framework of the cement hydration products increasing the bonding between silica fume particles and cement. The optimum mix containing 0.3% GO with 15% WO replacement exhibited extensive C-S-H formation along with a uniform densified structure indicating that calcium meta-silicate has filled the pores.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.56 no.2
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• pp.151-161
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• 2023

This study examined the nutritional characteristics of commercial Sik-hae (CS). The proximate composition per 100 g of CS: 12.7±3.8 g crude protein, 4.4±1.0 g crude lipid, and 6.0±1.2 ash. The total amino acid content range and average per 100 g of CS were 5.65-16.32 g and 11.69±3.76 g, respectively, and the major amino acids were aspartic acid and glutamic acid in all products. The major fatty acids of CS were 16:0 (all products), 18:1n-9 [8 types, flounder sik-hae (FS, all products), sandfish sik-hae (SS), anchovy sik-hae (AS) and black edged sculpin sik-hae (BESS)], 18:2n-6 (9 types, excluding AS), 20:5n-3 (4 types, FS-1, 2, 3, 5), and 22:6 [3 types, FS-3, Alaska pollock sik-hae (APS)-1 and AS]. As a supply source of mineral, 7 types (FS-1, 2, 3, 5, SS, AS and BESS) of calcium, 9 types [FS (all products), APS-1, SS, AS and BESS] of phosphorus, 6 types (FS-1, 3, 5, APS-1, SS and AS) of magnesium and 5 types (FS-1, 4, APS-2, SS and AS) of iron were expected.

• Food Science of Animal Resources
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• v.43 no.2
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• pp.232-244
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• 2023

We investigated the effects of different phosphate replacements on the quality of ground pork products cured with sodium nitrite or radish powder to determine their potential for achieving clean-label pork products. The experimental design was a 2×5 factorial design. For this purpose, the ground meat mixture was assigned into two groups, depending on nitrite source. Each group was mixed with 0.01% sodium nitrite or 0.4% radish powder together with 0.04% starter culture, and then processed depending on phosphate replacement [with or without 0.5% sodium tripolyphosphate; STPP (+), STPP (-), 0.5% oyster shell calcium (OSC), 0.5% citrus fiber (CF), or 0.5% dried plum powder (DPP)]. All samples were cooked, cooled, and stored until analysis within two days. The nitrite source had no effect on all dependent variables of ground pork products. However, in phosphate replacement treatments, the STPP (+) and OSC treatments had a higher cooking yield than the STPP (-), CF, or DPP treatments. OSC treatment was more effective for lowering total fluid separation compared to STPP (-), CF, or DPP treatments, but had a higher percentage than STPP (+). The STPP (+) treatment did not differ from the OSC or CF treatments for CIE L^* and CIE a^*. Moreover, no differences were observed in nitrosyl hemochrome content, lipid oxidation, hardness, gumminess, and chewiness between the OSC and STPP (+) treatments. In conclusion, among the phosphate replacements, OSC addition was the most suitable to provide clean-label pork products cured with radish powder as a synthetic nitrite replacer.

• Analytical Science and Technology
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• v.22 no.1
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• pp.92-100
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• 2009

Azacrown resins were synthesized by mixing 1-aza-12-crown-4 macrocyclic ligand into styrene (2th petroleum in 4th class hazardous materials) divinylbenzene (DVB) copolymer with crosslinkage of 1%, 2%, 5% and 10% by substitution reaction. The synthesis of these resins was confirmed by content of chlorine, element analysis, thermogravimetric analysis (TGA), surface area (BET), and IR-spectroscopy. The effects of pH, time, crosslinkage of resins and dielectric constant of solvent on adsorption of metal ions by resin adsorbent were investigated. Metal ions showed a great adsorption over pH 3 and adsorption equilibrium of metal ions was about two hours. In addition, adsorptive selectivity of metals on the resin in ethanol solvent was increased in the order of ${UO_2}^{2+}$ > $Ca^{2+}$ > $Sm^{3+}$ ion and adsorption of uranium ion was decreased with increase of crosslinkage such as 1%, 2%, 5% and 10% and was inversely proportional to the order of dielectric constant of solvents.