• Journal of the Korean Applied Science and Technology
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• v.33 no.4
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• pp.802-812
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• 2016

Silicone foam is very useful as flame resistant material for many industrial areas such as high performance gasketing, thermal shielding, vibration mounts, and press pads. A silicone foam was prepared through simultaneous crosslinking and foaming by hydrogen condensation reaction of a vinyl-containing polysiloxane (V-silicone) and a hydroxyl-containing polysiloxane (OH-silicone) with hydride containing polysiloxane (H-silicone) in the presence of platinum catalyst and imorganic filler at room temperature. This is more convenient process for silicone foam manufacturing than the conventional separated crosslinking and foaming systems. Funtionalized silicones we used in this experiment were consisted with a V-silicone containing 1,0 meq/g of vinyl groups and a viscosity of 20 Pa-s, an OH-silicone with 0.4 meq/g of hydroxyl groups and a viscosity from 50 Pa-s, and an H-silicone containing 7.5 meq/g of hydride groups and a viscosity of 0.06 Pa.s. The effects of compositions of functionalized silicones and additives, such as catalyst and filler on the structure and mechanical properties of silicone foam were studied. 0.5 wt% of Pt catalyst was enough to accelerate the foaming rate of silicone resins. The addition of OH-silicone with lower viscosity accelerates the initial foaming rate and decreases the foam density, but the addition of V-silicone with lower viscosity reduces the tensile strength as well as the elongation. The final foam density, tensile strength, and elogation of silicone foam prepared under the SF-3 condition increase maximum to $0.58g/cm^3$, $3,51kg_f/cm^2$, and 176 %, repectively. We found out the filler alumina also played an important role to improve the mechanical properties of silicone foams in our foaming system.

• Journal of Life Science
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• v.28 no.10
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• pp.1244-1253
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• 2018

Rumen microbiome consists of a wide variety of microorganisms, such as bacteria, archaea, protozoa, fungi, and viruses, that are in a symbiotic relationship in a strict anaerobic environment in the rumen. These rumen microbiome, a vital maker, play a significant role in feed fermentation within the rumen and produce different volatile fatty acids (VFAs). VFAs are essential for energy metabolism and protein synthesis of the host animal, even though emission of methane gas after feed fermentation is considered a negative indicator of loss of dietary energy of the host animal. To improve rumen microbial efficiency, a variety of approaches, such as feed formulation, the addition of natural feed additives, dietary feed-microbes, etc., have taken to increase ruminant performance. Recently with the application of high-throughput sequencing or next-generation sequencing technologies, especially for metagenomics and metatranscriptomics of rumen microbiomes, our understanding of rumen microbial diversity and function has significantly increased. The metaproteome and metabolome provide deeper insights into the complicated microbial network of the rumen ecosystem and its response to different ruminant diets to improve efficiency in animal production. This review summarized some recent advances of rumen microbiome techniques, especially "meta-omics," viz. metagenomic, metatranscriptomic, metaproteomic, and metabolomic techniques to increase feed fermentation and utilization in ruminants.

• Asian-Australasian Journal of Animal Sciences
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• v.33 no.6
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• pp.981-991
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• 2020

Objective: To evaluate calcium stearoyl-2 lactylate (CSL) performance as an exogenous emulsifier together with lipase for broiler diets. Methods: In total, 252 one-day-old Ross 308 broiler chickens were allocated in a completely randomized design to give 6 replications per treatment with 7 birds in each cage. There were six dietary treatments representing a 2×3 factorial arrangement consisted of two energy levels (standard energy [positive control, PC] and -100 kcal/kg of the requirement level [negative control, NC]) and three dietary treatments (without additives [CON], CON+CSL [CSL], and CON+CSL+lipase [CSL-Lipase]). Corn and soybean meal-based experimental diets containing vegetable oil were formulated. Growth performance, blood parameters, visceral organ weights, ileal morphology, nutrient digestibility, and cytokine gene expression were measured. Results: Birds fed a diet including CSL increased (p<0.05) lipase level in blood compared to birds fed a diet including CSL-Lipase on day 21. Similarly, higher (p<0.05) liver weight was observed in birds fed a diet including either CSL or CSL-Lipase on day 21. Birds fed NC diet with CSL improved (p<0.05) nutrient digestibility compared to the NC diet on day 21. However, birds fed a diet supplemented with CSL or CSL-Lipase did not affect (p>0.05) the weight gain, feed efficiency, ileal morphology, and cytokine concentrations during the experiment period, regardless of dietary energy levels. Conclusion: Our results indicated that CSL has a role in improving nutrient digestibility in young birds when supplemented to a corn-soybean meal based broiler diet.

• Journal of Korean Tunnelling and Underground Space Association
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• v.20 no.2
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• pp.453-467
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• 2018

The excavation performance and the cutting tool wear prediction of shield TBM are very important issues for design and construction in TBM tunneling. For hard-rock TBMs, CSM and NTNU model have been widely used for prediction of disc cutter wear and penetration rate. But in case of soft-ground TBMs, the wear evaluation and the excavation performance have not been studied in details due to the complexity of the ground behavior and therefore few testing methods have been proposed. In this study, a new soil abrasion and penetration tester (SAPT) that simulates EPB TBM excavation process is introduced which overcomes the drawbacks of the previously developed soil abrasivity testers. Parametric tests for penetration rate, foam mixing ratio, foam concentration were conducted to evaluate influential parameters affecting TBM excavation and also ripper wear was measured in laboratory. The results of artificial soil specimen composed of 70% illite and 30% silica sand showed TBM additives such as foam play a key role in terms of excavation and tool wear.

• Journal of the Korean Electrochemical Society
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• v.19 no.1
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• pp.1-8
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• 2016

Capacity of layered lithium nickel-cobalt-manganese oxide ($LiNi_{1-x-y}Co_xMn_yO_2$) cathode material can increase by raising the charge cut-off voltage above 4.3 V vs. $Li/Li^+$, but it is limited due to anodic instability of conventional electrolyte. We have been screening and evaluating various sulfone-based compounds of dimethyl sulfone (DMS), diethyl sulfone (DES), ethyl methyl sulfone (EMS) as electrolyte additives for high-voltage applications. Here we report improved cycling performance of $LiNi_{0.5}Co_{0.2}Mn_{0.3}O_2$ cathode by the use of dimethyl sulfone (DMS) additive under an aggressive charge condition of 4.6 V, compared to that in conventional electrolyte, and cathode-electrolyte interfacial reaction behavior. The cathode with DMS delivered discharge capacities of $198-173mAhg^{-1}$ over 50 cycles and capacity retention of 84%. Surface analysis results indicate that DMS induces to form a surface protective film at the cathode and inhibit metal-dissolution, which is correlated to improved high-voltage cycling performance.

• Applied Chemistry for Engineering
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• v.28 no.6
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• pp.655-662
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• 2017

Sulfide photocatalysts, CdS and CdZnS, were synthesized using a simple precipitation method and their photocatalytic activities were evaluated by the degradation of rhodamine B under visible light irradiation. The effects of four inorganic salt additives, KCl, NaCl, $K_3PO_4$, and $Na_3PO_4$, on the photocatalytic reaction were examined and the role of $K^+$, $Na^+$, $Cl^-$ and $PO_4{^{3-}}$ ions during photocatalytic reaction was discussed. The added inorganic salts were shown to have a remarkable effect on the photocatalytic reaction. It was also found that the anions in inorganic salts have a much more profound effect on the reaction rate, as compared to the cations. Under the present experimental conditions, $PO_4{^{3-}}$ revealed a significant inhibitory effect on the degradation rate whereas $Cl^-$ enhanced the rate slightly. This work pointed out that the consideration of additive effects is needed in the photocatalytic reaction for wastewater treatment.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.12 no.4
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• pp.315-327
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• 2007

This study investigated temporal and spatial variation of Pb and stable Pb isotopes accumulated in Ulleung Basin core sediments (4) using MC ICP/MS in order to identify the sources of anthropogenic Pb in the East/Japan Sea. Leached (1M HCl) Pb concentration and isotope ratios ($^{207}Pb/^{206}Pb\;and\;^{208}Pb/^{206}Pb$) were nearly constant during 300 yrs past than 1930, but increased up to twice in concentration and as much as 3.41% (1.70%) after 2000. On the other hand, residual Pb concentrations were nearly constant for past 400 yrs. The accumulation rates of anthropogenic Pb in the basin area were in the range of $3.1-3.5mg/m^2/yr$, which were similar levels to total atmospheric Pb deposition fluxes from 1990s to the present. In the slope area, more increase of anthropogenic Pb accumulation than the levels expected from mass accumulation rate could be found after the middle of 1990s. From the detailed evaluation for the temporal and spatial variation of accumulation rate and isotope ratios of anthropogenic Pb, we proposed probable sources and pathways of anthropogenic Pb. Pb emmision by coal burning from the China and Korea initiated the accumulation of anthropogenic Pb in the sediments of East/Japan Sea from 1930s. The accumulation of Pb increased by the addition of anti-nocking agents from both countries untill the beginning of 1990s, but from the middle of 1990s to the present, the phase-out of gasoline additives and the rapid increase of coal burning from the China maintained the atmospheric Pb levels in the Ulleung basin nearly similar to before. However, the local sources within this basin might take an important role in the rapid increase of anthropogenic Pb accumulation in slope areas from the middle of 1990s.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.19 no.5
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• pp.459-468
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• 1986

This study was attempted to process low-sodium salt fermented small shrimp as substitutes for traditional high-sodium salt fermented one which has widely been favored and consumed in Korea. Low-salt fermented small shrimp was prepared with $4\%$ sodium chloride and $4\%$ potassium chloride, and various additives such as $0.5\%$ lactic acid, $6\%$ sorbitol and $4\%$ ethylalcohol extract of red pepper as preservatives and flavor enhancers. And the changes of taste compounds, volatile compounds and fatty acid composition in low-salt fermented small shrimp were analyzed and compared with those of conventional $20\%$ sodium salt fermented one during the fermentation of 120 days at $25{\pm}3^{\circ}C$. The most favorable taste for fermented small shrimp were reached at 60 days of fermentation. Judging from sensory evaluation, little difference of taste was detected between the low-salt fermented small shrimp and high-sodium salt fermented one. The principal taste compounds in fermented small shrimp were free amino acids, and betaine and nucleotides and their related compounds played an assistant role. The major amino acids in fermented small shrimp were glutamic acid, leucine, proline, glycine, lysine and aspartic acid. The major fatty acids in fermented small shrimp samples were 16:0, 20:5, 22:6, 16:1 and 18:1, and unsaturated fatty acids decreased slightly while saturated fatty acids increased during fermentation. At 60 days of fermentation 8 kinds of volatile fatty acids (acetic acid, propionic acid, isobutyric acid, butyric acid, isovaleric acid, valeric acid, isocarproic acid, carproic acid), 6 kinds of carbonyl compounds (ethanal, propanal, 2-methylpropanal, 3-methylbutanal, pentanal, 2-methylpentanal), and 3 kinds of volatile amines (methylamine, trimethylamine, isopropylamine) were identified.

• Journal of the Korean Society of Food Science and Nutrition
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• v.18 no.4
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• pp.355-362
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• 1989

For the effective utilization of mackerel as a food sauce, the processing conditions of the frozen seasoned mackerel meat and the changes in taste compounds during its frozen storage were investigated. To prepare the frozen seasoned mackerel meat, the mackerel was headed, gutted manually, washed with tap water and deboned with the meat seperator. Then it was mixed with additives such as emulsion curd(32.1%, w/w), table salt(0.5%, w/w), sugar(2.0%, w/w), sodium bicarbonate(0.4%, w/w), polyphosphate(0.2%, w/w), monosodium glutamate(0.2%, w/w), onion powder(0.3%, w/w), garlic powder(0.1%, w/w), ginger powder(0.1%, w/w), soybean protein(3.0%, w/w) and sodium erythorbate(0.1%, w/w). This seasoned fish meat was frozen with contact freezer, packed In a carton box, and then stored at $-25^{\circ}C$. The moisture and lipid contents in the products were 70.8-71.7% and 10.9-11.3%, respectively. The taste compounds of the frozen seasoned mackerel meat were free amino acids(1625.0-1692.0mg/100g), nucleotides and their related compounds(316.6-366.8 mg/100g) as well as total creatinine(270.2-311.8 mg/100g), and small amount of betaine and TMAO. In free amino acids, the predominant ones were histidine, lysine, glutamic acid and arginine. It was supposed from the results that principal taste compounds of frozen seasoned mackerel meat were free amino acids, and that total creatinine, TMAO, TMA and betaine as well as nucleotides and their related compounds also played an assistant role.