• Nuclear Engineering and Technology
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• v.55 no.10
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• pp.3665-3676
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• 2023

The use of ion exchange resins to remove ionic impurities from solution is prevalent in industrial process systems, including in the primary heat transport system (PHTS) purification circuit of nuclear power plants. Despite its extensive use in the nuclear industry, our general understanding of ion exchange cannot fully explain the complex chemistry in ion exchange beds, particularly when operated at or near their saturation limit. This work investigates the behaviour of mixed-bed ion exchange resin, saturated with species representative of corrosion products in a CANDU (Canadian Deuterium Uranium) reactor PHTS, particularly with respect to iron chemistry in the resin bed and the removal of lithium ions from solution. Experiments were performed under deaerated conditions, analogous to normal PHTS operation. The results show interesting iron chemistry, suggesting the hydrolysis of cation resin bound ferrous species and the subsequent formation of either a solid hydrolysis product or the soluble, anionic Fe(OH)₃^-.

• Nuclear Engineering and Technology
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• v.55 no.10
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• pp.3808-3814
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• 2023

The thermal stability of nitric acid solutions after contact with non-irradiated and irradiated tributyl phosphate (TBP) and its solution in Isopar-M has been studied. It has been established that exothermic processes occur during heating due to the interaction of soluble radiolysis products and the decomposition of the extractant with nitric acid. Such processes can occur at temperatures below 100 ℃, but unlike a thermal explosion that occurs in seconds, they are longer in time and are accompanied by weak heat evolution. Their intensity depends on the composition of the extractant, the concentration of HNO₃, and the volume ratio of the organic and aqueous phases. The presence of extractant degradation products in raffinates does not pose a risk of a rapid evolution of gaseous products during evaporation, however, the presence of reducing agents can significantly increase the intensity of the exothermic decomposition of raffinates.

• Korean Journal of Soil Science and Fertilizer
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• v.1 no.1
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• pp.1-5
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• 1968

A low yielding paddy soil was water logged at $30{\pm}2^{\circ}C$ with soluble starch as a easily decomposable organic matter for 3 weeks in the laboratory. The relation of pH and Eh changes and soluble iron, manganese and silica was investigated. The experimental results obtained were summarized as follows; 1. When organic matter was applied, reduction of the soil was severer, that is, Eh value was lower by 200 mv. for a week in the beginning of submergence. 2. pH of the untreated soil was dropped a little just after submergence, and then gradually increased to 60. When treated, pH was increased due to abrupt drop of Eh in the beginning but decreased to 4.5 after a week, and became constant at this pH value. 3. Slight increase in soluble iron, manganese and silica was observed in the untreated soil whereas soluble iron, manganese and silica in the treated soil were increased about 20, 10, and 3 times, respectively. 4. When soluble starch was treated, pH and soluble silica or manganese was highly correlated[($H^+$) and Mn ${\gamma}=0.734^{**}$, ($H^+$) and $SiO_2$ ${\gamma}=0.923^{**}$] and below pH 5.0, release of these element was rapidly increased.

• Animal Bioscience
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• v.35 no.12
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• pp.1892-1903
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• 2022

Objective: A series of experiment were conducted to evaluate the effects of replacing a part of soybean meal (SBM) at 6% of broiler diets with fermented soybean meal (FSBM) obtained by single or two-stage fermentation by measuring growth performance, antioxidant activity in the jejunum and distal intestinal microflora. Methods: Soybean meal samples were prepared by single-stage fermentation using Bacillus velezensis (Bv) (FSBM_B), or Lactobacillus spp. (as commercial control) (FSBM_L). Additional SBM sample was prepared by two-stage fermentation using Bv and subsequently using Lactobacillus brevis ATCC 367 (Lb) (FSBM_B+L). Enzyme activity, chemical composition, trichloroethanoic acid-nitrogen solubility index (TCA-NSI) and antioxidant activity were measured. Then, in an in vivo study, 320 Ross308 broilers were divided into four groups with ad libitum supply of feed and water. Four groups were fed either a corn-soybean meal diet (SBM), or one of fermented SBM diets (FSBM_B+L, FSBM_B, and FSBM_L). Growth, serum characteristics, microflora, and the mRNA expression of selected genes were measured. Results: Compared to SBM, FSBM_B+L contained lower galacto-oligosaccharide, allergic protein, and trypsin inhibitor, and higher TCA-NSI by about three times (p<0.05). Reducing power and 1,1-diphenyl-2-picrylhydrazyl free radical scavenging ability correlated positively with the TCA-NSI content in FSBM. Growth performances were not significantly different among four groups. In jejunum of 35-day-old broilers, partial replacement of SBM by FSBM_B+L increased the activity of superoxide dismutase and catalase (CAT), and the FSBM_B group had the highest catalase activity (p<0.05). Partial replacement of SBM by FSBM increased relative mRNA expressions of nuclear factor erythroid 2-related factor 2 (Nrf2), heme oxygenase-1 (HO-1), and peptide transporter 1 (PepT1) (p<0.05); however, FSBM_B+L increased CAT mRNA level to 5 times of the control (p<0.05). Conclusion: Using Bv- and Lb-processed SBM through two-stage fermentation to partially replace 6% of diets will improve the gut's antioxidant activity under commercial breeding in broilers.

• Korean Journal of Pharmacognosy
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• v.46 no.3
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• pp.234-242
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• 2015

Allium hookeri (Liliaceae), native to India is widely cultivated in Korea lately as a medicinal plant. This study was performed to evaluate the antioxidant and lifespan extending effects of the root of A. hookeri. Methanol extract from the root of A. hookeri was successively partitioned as methylene chloride, ethyl acetate, n-butanol and H₂O soluble fractions. Antioxidant effects of the fractions were measured by measuring the radical scavenging effect on 1,1-diphenyl-2-picrylhydrazyl (DPPH), and superoxide quenching activities. Lifespan extending effects of the fractions were investigated using Caenorhabditis elegans model system. In addition, stress resistant, superoxide dismutase (SOD) and catalase activities, and intracellular reactive oxygen species (ROS) levels were also studied. Furthermore, we had investigated aging-related factors such as reproduction, food intake, growth and movement of C. elegans to find any sample-induced significant change. Our results revealed that ethyl acetate soluble fraction from the root of A. hookeri showed the most potent antioxidant and lifespan extending effects, and this fraction elevated the most potent SOD and catalase activities of worms, and reduce intracellular ROS accumulation.

• Journal of Environmental Science International
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• v.7 no.5
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• pp.707-716
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• 1998

The chemical characteristics of precipitation was investigated in Pusan area. Samples were collected from January to November in 1996 at 4 sites, and analyzed pH, major soluble ionic components(C $l^{[-10]}$ , N $O_3$$^{[-10]}$ , S $O_4$$^{2-}$, N $a^{+}$, $K^{+}$, N $H_4$$^{+}$, $Mg^{2+}$, $Ca^{2+}$). The order of anion and cation concentrations for the initial precipitation were C $l^{[-10]}$ ＞ S $O_4$$^{2-}$ ＞ N $O_3$$^{[-10]}$ , and $Ca^{2+}$ ＞ N $a^{+}$ ＞ N $H_4$$^{+}$ ＞ $Mg^{2+}$ ＞ $K^{+}$, respectively. At coastal sites(P1 and P2) C $l^{[-10]}$ and N $a^{+}$ of maritime sources (seasalt) were high, but at inland sites(P3 and P4) nss-C $a^{2+}$ and nss-S $O_4$$^{2-}$ were high. Calcium ion for the initial precipitation showed high value of enrichement factor(EF) relative to seawater composition. The contribution of seasalt to the composition of precipitation was higher at bite P1 (53.5%) than those of the other sites. Throughout the year the concentrations of major ions for the initial precipitation were low in the heavy rain season. The mean pH for the initial precipitation was 5.4 and showed the negative relationship with the precipitaion amount. The S $O_4$$^{2-}$ and N $O_3$$^{[-10]}$ do not play an important role in rain acidification due to the high(97%) neutralizing effect of amonia and calcium species.and calcium species.

• The Korean Journal of Food And Nutrition
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• v.33 no.5
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• pp.576-583
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• 2020

The purpose of this study was to compare the quality characteristics of silken tofu products from the commercial market in Korea. Seven types of commercial silken tofu were sampled and their physicochemical properties, including soluble solid contents, salinity, pH, total acidity, moisture contents (total solid contents), crude protein and fat contents were evaluated. The TPA results suggest that the texture of silken tofu was very different from one another according to the type of and the amount of coagulant. The commercial silken tofu showed a range of pH 5.53~6.48, total acidity of 0.12~0.32%, soluble solid contents of 2.62~5.07 °Brix, salinity of 2.28~4.30%, and moisture contents of 87.10~92.24%, respectively. In terms of the coagulant of tofu, besides the GDL (glucono-δ- lactone), other coagulants such as MgCl₂ for making 'silken tofu' in the Korean tofu market. The quality characteristics differed depending on the constituents of sample and the coagulants of tofu used. These results are expected to be useful in identifying new trends in the domestic silken tofu industry.

• Korean Journal of Breeding Science
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• v.43 no.2
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• pp.120-125
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• 2011

A field experiment was conducted to examine the fruit quality characters in second generation ($F_2$) hybrid cultivar and to compare the fruit characters with original $F_1$ hybrid cultivar of minipaprika (yellow and orange type) at the Research Farm, Hwacheon in July, 2010. Fruit characters varied within $F_2$ population of each minipaprika type. In minipaprika yellow, fruit weight varied from 12.2 g to 50.8 g (average 28.5 g) and fruit length/width varied from 1.4 to 2.8 (average, 2.0). Pericarp thickness ranged from 1.8 mm to 4.1 mm (average, 2.9 mm). Total soluble solid (TSS) varied from $6.2^{\circ}Brix$ to $13.5^{\circ}Brix$ with an average of $8.7^{\circ}Brix$. Fruit volume varied from 10.3 cc to 46.7 cc with an average of 24.4 cc. In minipaprika orange type, fruit weight ranged from 19.7 g to 42.4 g (average, 29.0 g) and fruit length/width varied from 1.5 to 2.6 (average, 2.0). Pericarp thickness varied from 2.1 mm to 4.1 mm with an average of 3.0 mm. TSS varied from $5.0^{\circ}Brix$ to $12.2^{\circ}Brix$ (average, $7.9^{\circ}Brix$) and average fruit volume was 24.6 cc ranging from 10.7 cc to 35.0 cc. The average fruit quality characters in $F_2$ population in both yellow and orange minipaprika did not differ from their $F_1$ hybrid parent and $F_2$ seed can be an additional way to supply high yielding hybrid cultivars at lower cost to the minipaprika growers.

• Korean Journal of Breeding Science
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• v.42 no.4
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• pp.344-350
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• 2010

Sweet pepper inbred lines (KNU1003, KNU1006, KNU1007, KNU1009, KNU1015, KNU1017 and KNU2006) developed at Kangwon National University (KNU) through conventional means, inbred lines (5AVS1, 5AVS2, 5AVS3, 5AVS5, 5AVS7 and 5AVS8) collected at Rural Development Administration (RDA) and inbred lines (SP12, SP27 and SP14) derived from anther culture were used as female parents and anther culture derived homozygous lines (SP9, SP10, SP14, SP24, SP25, SP27, SP30, SP32, SP34, SP38, SP43, SP45 and SP51) were used as male parents to produce $F_1$ hybrids. A total of 37 $F_1$ hybrids were evaluated for fruit yield and quality characters in summer season, 2007. Variation in fruit number, fruit weight, fruit yield per plant and fruit volume was observed among the $F_1$ hybrids. Superiority on yield over standard/commercial varieties were differed among $F_1$ hybrids. Hybrid $5AVS8{\times}SP45$ exhibited highest heterosis over Special (16.5%) and Fiesta (24.7%). Fruit quality characters (fruit length, fruit width, pericarp thickness, total soluble solid, fruit shape and fruit color) were varied among the $F_1$ hybrids. Fruit number, fruit weight and fruit volume per plant were correlated with fruit yield. Based on the standard heterosis expressed by the hybrids and quality characters evaluation, $KNU1017{\times}SP27$, $5AVS1{\times}SP43$, $5AVS5{\times}SP27$, $5AVS8{\times}SP45$, $SP12{\times}SP38$ and $SP27{\times}SP25$ hybrids were found to be superior over commercial cultivars and are selected. Inbred lines of these hybrid combinations can be used to produce $F_1$ hybrid seed for commercial production.

• The Korean Journal of Food And Nutrition
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• v.35 no.6
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• pp.521-530
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• 2022

This study was conducted to compare the quality characteristics of commercial tofu products from the market in Korea. Seventeen types of commercial tofu samples were taken and their physicochemical properties, including soluble solid contents, salinity, pH, total acidity and moisture (total solid contents), were analyzed. The hardness of tofu was negatively correlated with the moisture contents of tofu (r=-0.667^**). The commercial tofu showed pH 5.80~6.24, total acidity of 0.016~0.034%, soluble solids of 1.50~3.45°Brix, salinity of 1.20~2.30%, and moisture content of 79.91~87.57%, respectively. All 17 tofu samples sold in the Korean market were prepared using crude MgCl₂ and sea water as a coagulant. The quality characteristics vary depending on the constituent's of soybeans, and the ratio and amount of coagulants of tofu used. The origin of soybean seeds affected the yellowness of tofu; tofu made from imported soybean showed a higher b value than domestic soybean. These results are expected to be useful for understanding trends in the domestic tofu industry.