• Proceedings of the Korean Society of Propulsion Engineers Conference
• /
• 2011.11a
• /
• pp.745-749
• /
• 2011

Two-dimemsional liquid-solid multiphase fluid dynamics was used to analyze the suspension and mix of liquid fuel and solid particles in fuel tank installed mixing impeller. In this paper, the multiphase flow was modeled using Eulerian Grandular Multiphase model. Experimental measurements of the axial distribution of solids concentration in stirred tanks under 12vol% solid loading were used for comparison with the CFD simulation. Four cases for the impeller location and flow pumping direction also were reviewed under 10.5% solids loading and 700rpm in fuel mix tank. The result of quality of suspension was compared with each cases and the impeller location and operation of mixing fuel tank was established.

• Journal of the Korean Ceramic Society
• /
• v.32 no.2
• /
• pp.155-162
• /
• 1995

Solid oxide electrolytes of the MCe1-xGdxO3-x/2 (M: Ba, Mg. x=0.0-0.20) system were prepared using powders synthesized by the "liquid mix" method and calcined from the cross-linked polyacrylic polymer. The specimens were analyzed using XRD and SEM with EDX, and the sintering behavior of the electrolytes and their electrical conductivity were also studied. Although Mg-cerate is relatively inferior to Ba-cerate in the sinterability and chemical homogenity(EDX analysis data), both the Ba- and the Mg-cerate electrolytes at 80$0^{\circ}C$ show their maximum conductivities at x=0.10 and their values are in the same order of magnitude, i.e., 3.5$\pm$0.17.10-2(ohm.cm)-1.ohm.cm)-1.

• Korean Journal of Optics and Photonics
• /
• v.28 no.5
• /
• pp.221-228
• /
• 2017

We measured the refractive index of a mixed polymer (NOA61, NOA84) in the liquid and solid states. First we made a hollow prism and filled it with UV (ultraviolet) epoxy. Measurement of the apex angle and the minimum-deviation angle gave the refractive index of the liquid polymer. To measure the refractive index of the solid polymer, an additional structure was included in the hollow prism, and the UV epoxy filling in the hollow prism was hardened. In both cases of liquid and solid polymers, the refractive index of the mixed polymer turned out to be proportional to the mix ratio. These results provide a method to vary the focal length of a double stacked cylindrical microlens array using UV epoxy.

• Journal of Environmental Science International
• /
• v.19 no.2
• /
• pp.255-260
• /
• 2010

A stabilization/solidification (S/S) process for lead (Pb) contaminated soils was evaluated using waste cow bone containing apatite like compounds. Soil samples obtained form firing range were treated with waste cow bone. The effectiveness of stabilization was evaluated based on the Korean Standard Leaching Test (KSLT) and soil pH. The leached concentration reduced with increased in dose of waste cow bone. Overall, the KSLT results showed that Pb concentration in soils are significantly affected by amount of waste cow bone. When soil amended with 20 % of waste cow bone, less than 0.1 mg/kg was leached, and soil pH was increased from 6.5 to 8.4. Same results were obtained when finer waste cow bone was applied. The reachable concentration of Pb in soil showed in inversely proportional to solid/liquid ratio. Aging periods indicate improving mix design was applied. Relatively high lead concentrations was observed at the first 1 days, however leaching profile are reduced significantly over time for all mix designs.

• Journal of the Korean Ceramic Society
• /
• v.51 no.5
• /
• pp.424-429
• /
• 2014

YAG:$Ce^{3+}$ phosphor powders were synthesized using $Al(OH)_3$ seeds by means of a PVA-polymer-solution route. Various types of PVA with different molecular weights (different polymerization) were used. All dried precursor gels were calcined at $500^{\circ}C$ and then heated at $1500^{\circ}C$ in a mix of nitrogen and hydrogen gases. The final powders were characterized via XRD, SEM, PSA, PL, and PKG analyses. The phosphor properties and morphologies of the synthesized powders were dependent on the PVA type. As the molecular weight of the PVA was increased, the particle size gradually decreased with agglomeration, and the luminous intensity of the phosphor increased. However, the phosphor powder prepared from the PVA exhibiting very high molecular weight, showed a 531 nm (blue) shift from the 541 nm (yellow) wavelength of the YAG:$Ce^{3+}$ phosphor. Finally, the synthesized YAG:$Ce^{3+}$ phosphor powder prepared from the PVA with 89,000 - 98,000 molecular weight showed phosphor properties similar to those of a commercial phosphor powder, but without a post-treatment process.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.19 no.5
• /
• pp.146-152
• /
• 2018

In this study, to improve the performance of asphalt mixtures for plastic deformation occurring mainly in Korea, complex modifiers were prepared by mixing powders and liquid type modifiers. The main constituents were powdery diatomaceous earth, mica and carbon black, and liquid type solid 70% SBR latex. The tensile strength ratios for the two asphalt mixtures used in the test were above 0.80 for the Ministry of Land Transportation (2017) asphalt mixture production and construction guidelines. The effects of increasing the tensile strength in the dry state was more than 14% when the composite modifier was added. The deformation rate per minute by the wheel tracking test load was an average of 0.07 to 0.147 for each mixture. The strain rate per minute was improved by the modifier, and the dynamic stability was improved by almost 100% from 295 to 590. In addition, the final settling was reduced from 11.38 mm to 9.57 mm. A plastic deformation test using the triaxial compression test showed that the amount of deformation entering the plastic deformation failure zone at the end of the second stage section and in the third stage plastic deformation section was 1.76 mm for the conventional mixture and 1.50 mm for the complex modifier mixture. The average slope of the complex modifier asphalt mixture mixed with the multi-functional modifier was 0.005 mm/sec. The plastic deformation rate is relatively small in the section where the road pavement exhibits stable common performance, i.e. the traffic load.

• Korean Journal of Pharmacognosy
• /
• v.52 no.3
• /
• pp.192-201
• /
• 2021

Dangguisu-san (DGSS) is widely known traditional herbal medicinal formula in Korea for treatment of traumatic injury by traffic accident, ecchymosis, abdominal distension and anti-thrombosis of blood. This study was conducted to develop the simultaneous analyze method using high performance liquid chromatography (HPLC) and examine the effect of anti-inflammatory activity of DGSS-dry extract (DGSS-DE) and DGSS-mix extract powder (DGSS-MEP). Physicochemical characteristics of DGSS-DE and DGSS-MEP showed that there is no significant difference in pH, titratable acidity, total soluble solid content and browning degree except for color value (L, a, b). 15 functional constituents of DGSS were identified and the correlation coefficient values of DGSS-DE and DGSS-MEP were conformed 0.950. Also, DGSS-DE and DGSS-MEP significantly decreased the secretion of nitric oxide (NO), prostaglandin E₂ (PGE₂), interleukin-1β (IL-1β), interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α) through inhibited expression of inducible nitric oxide synthase (iNOS), cyclooxygenase-2 (COX-2), IL-1β, IL-6, and TNF-α. From these result, DGSS-MEP showed similar chemical composition and anti-inflammatory effect to DGSS-DE. Therefore, DGSS-DE and DGSS-MEP may be useful as potential source of drug to prevent inflammation.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.41 no.10
• /
• pp.1356-1362
• /
• 2012

UV-VIS spectrophotometric and high-performance liquid chromatographic (HPLC-DAD) methods were applied in order to identify and quantify the composition of polyphenols in commercial cocoa-containing products. Total polyphenolic contents of cocoa mix, choco-syrup, milk chocolate, and dark chocolate were evaluated using Folin-Ciocalteu's phenol reagent according to a UV-VIS spectrometric method. Antioxidant capacities of cocoa extracts by methanol were evaluated by 2,2'-azino-bis(3-ethyl benzothiazoline-6-sulfonic acid) (ABTS) assay and 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay. The obtained results show that the polyphenolic contents and antioxidant capacities of cocoa products and chocolates depend on solid cocoa content. Among the tested cocoa products and chocolates, the most abundant phenolic compound was epicatechin.

• Asian-Australasian Journal of Animal Sciences
• /
• v.17 no.5
• /
• pp.621-628
• /
• 2004

Twenty male buffalo calves of 6-9 months of age (average body weight, 97 kg) were randomly allocated into two main groups of four (control) and sixteen (supplemented) calves. The supplemented group was further divided in to four equal sub-groups, with the two groups supplemented with a liquid preparation of urea-molasses, UML1, containing fish meal and UML2, containing formaldehyde treated deoiled mustard cake (FDMC) and the other two, with a semi-solid preparation, UMC1 with FDMC and deoiled rice bran (DORB) contributing similar level of CP as in UML2 and UMC2 with double the level of FDMC to that in UMC1. The control group was fed with DORB along with ad libitum wheat straw at 40:60 ratios. The rest of the groups were fed on the above diet supplemented with 500 g (as fed basis) of urea-molasses preparations. The experimental feeding was carried out for 24 weeks including a metabolism trial towards the end of experimental feeding. Daily feed intake and fortnightly change in live weight were also recorded during the study. Catalytic supplementation of 500 g urea-molasses induced 8-25% higher voluntary feed intake of wheat straw, resulting in 15-25% higher DM and OM intake. The digestibility of DM, OM, total carbohydrate, NDF, ADF, hemicellulose and cellulose in all the dietary groups were comparable. The CP digestibility of calves in supplemented groups were higher (p<0.05) than the control group. The balance of nutrients, viz. N, Ca and P, was also higher in the supplemented groups. Significantly higher intake of digestible CP coupled with other digestible nutrients attributed to higher TDN (1.67-1.78 vs. 1.37 kg) and ME (5.94-6.31 vs. 4.87 Mcal) intake in urea-molasses supplemented groups which resulted in higher live weight gain compared to that in control group (p<0.01). Between the supplements, UML2 and UMC2 faired non-significantly, indicating formalin treated mustard cake as a suitable replacement to fishmeal in the supplement. The overall ranking based on intake and digestibility of nutrients, live weight gain, economic evaluation and input-output relationship revealed that the rations with UML2 and UMC1 to be of greater value compared to other types. From the study it can be concluded that young ruminants can be reared successfully on a basal diet of deoiled rice bran and wheat straw supplemented with cheaper urea-molasses-mineral mix.

• Journal of the Korean Electrochemical Society
• /
• v.24 no.4
• /
• pp.77-92
• /
• 2021

The energy density of lithium-ion batteries (LIBs) determines the mileage of electric vehicles. For increasing the energy density of LIBs, it is necessary to develop high-capacity active materials that can store more lithium ions within constrained weight. The rapid progress made in cathode technology has realized the utilization of the near-theoretical capacity of cathode materials. In contrast, commercial LIBs have still exploited graphite as active material in anodes since the 1990s. The most promising way to increase anodes' capacity is to mix high-capacity and long-cycle-life silicon oxides (SiOx) with graphite. However, the low initial Coulombic efficiency (ICE) of SiOx limits its content below 15 wt%, impeding the capacity increase in anodes. To address this issue, various prelithiation techniques have been proposed, which can improve the ICE of high-capacity anode materials. In this review paper, we introduce the principles and expected effects of prelithiation techniques reported so far. According to the reaction mechanisms, the strategies are categorized. Mainly, we focus on the recent progress of solution-based chemical prelithiation methods with commercial viability, of which lithiation reaction occurs homogeneously at liquid-solid interfaces. We believe that developing a cost-effective and mass-scalable prelithiation process holds the key to dominating the anode market for next-generation LIBs.