• Korean Chemical Engineering Research
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• v.43 no.5
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• pp.616-620
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• 2005

The morphology and photoluminescence characteristics of green light emitting hexaaluminate phosphor particles prepared by high temperature spray pyrolysis from spray solution with and without ammonium dihydrogen phosphate flux were investigated. The particles prepared from spray solution without flux material had hollow morphology at preparation temperatures between $900^{\circ}C$ and $1,650^{\circ}C$. Ammonium dihydrogen phosphate flux added into spray solution enabled the formation of particles with spherical shape and filled morphology at preparation temperatures between $900^{\circ}C$ and $1,650^{\circ}C$. The hexaaluminate phosphor particles with magnetoplumbite structure were directly prepared by spray pyrolysis from spray solution with ammonium dihydrogen phosphate flux above $1,600^{\circ}C$. Ammonium dihydrogen phosphate flux was effective in improving the photoluminescence intensity of the phosphor particles at low preparation temperatures. The phosphor particles prepared from spray solution with and without flux material by spray pyrolysis under reducing atmosphere at $1,650^{\circ}C$ had comparable photoluminescence intensities with that of the phosphor particles optimized by post-treatment.

• Journal of the Korea Concrete Institute
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• v.28 no.3
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• pp.299-308
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• 2016

This paper presents an investigation of the mechanical and microstructural properties on hardened samples that were synthesized using blended binder(fly ash(FA) and blast furnace slag cement(BFSC)), alkali activator and sea water or distilled water. Binders were prepared by mixing the FA and BFSC in different blend weight ratios of 6:4, 7:3 and 8:2. Sodium hydroxide and sodium silicate were used 5 wt% of binder, respectively, as an alkaline activator. The compressive strength and absorption were measured at the age of 3, 7 and 28 days, and the XRD, TGA and MIP tests were performed at the age of 28 days. An increase in the content of BFSC leads to an increase in the quantities of ettringite and C-S-H formed, regardless of the type of mixing water. And it also shows higher strength due to the reduction of pores larger than ~50 nm. All hardened samples in this study have common hydration products of C-S-H, $Ca(OH)_2$ and calcite. Hydrocalumite of all reaction products formed was only present in hardened sample mixed with sea water. For each FA/BFSC mixing ratio, the compressive strength of hardened sample mixed with sea water was similar to that mixed with distilled water. It is proposed that the slight increase of strength of samples mixed with sea water is mainly due to the presence of hydrocalumite phase containing chlorine ion, contributing to the change of total porosity and pore size distribution in samples.

• Journal of the Korean Society of Food Science and Nutrition
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• v.41 no.1
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• pp.116-122
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• 2012

Volatile flavor compounds derived from four black garlic extracts purchased in a local market were analyzed for the purpose of quality assessment. A total of 68 compounds was detected in samples using solid phase microextraction (SPME)/GC/MSD, and they were mainly sulfur-containing compounds, including three unknown compounds (21), aldehydes (10), furans (7), alcohols (6), aromatic compounds (7), ketones (4), acids (4), nitrogen-containing compounds (3), esters (2), and miscellaneous compounds (4). 2,6-Dimethyl-4-heptanone having a fruity-sweet odor was the most abundant in all of the samples. Six sulfur-containing compounds including allyl sulfide, 4-methyl-1,2,4-thiazole, 1,3,5-trithiane, unknown I (RI 1564), unknown II (RI 1565), and unknown III (RI 1613) were detected in all of the samples and appeared to contribute to the garlic-like odor. Particularly, three aldehydes (3-methylbutanal, benzaldehyde, phenylacetaldehyde), four furans (furfural, 2-acetylfuran, 5-methyl-2-furfural, furfural alcohol), and others (2,6-dimethylpyrazine, acetic acid) formed through a Maillard reaction during garlic aging were detected in all of the samples, and they contributed to the characteristic burnt, sweet, and sour flavors of black garlic extracts.

• Applied Chemistry for Engineering
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• v.24 no.5
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• pp.443-455
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• 2013

Electrochemical studies on charge transfer reactions across the interface between two immiscible electrolyte solutions (ITIES) have greatly attracted researcher's attentions due to their wide applicability in research fields such as ion sensing and biosensing, modeling of biomembranes, pharmacokinetics, phase-transfer catalysis, fuel generation and solar energy conversion. In particular, there have been extensive efforts made on developing sensing platforms for ionic species and biomolecules via gelifying one of the liquid phases to improve mechanical stability in addition to creating microscale interfaces to reduce ohmic loss. In this review, we will mainly discuss on the basic principles, applications and future aspects of various sensing platforms utilizing ion transfer reactions across the ITIES. The ITIES is classified into four types : (i) a conventional liquid/liquid interface, (ii) a micropipette supported liquid/liquid interface, (iii) a single microhole or an array of microholes supported liquid/ liquid interface on a thin polymer film, and (iv) a microhole array liquid/liquid interface on a silicon membrane. Research efforts on developing ion selective sensors for water pollutants as well as biomolecule sensors will be highlighted based on the use of direct and assisted ion transfer reactions across these different ITIES configurations.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.4
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• pp.1699-1702
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• 2014

Objective: To evaluate clinical efficacy of a dose escalating schedule of paclitaxel concurrent with radiotherapy in treating patients with locally advanced non-small cell lung (NSCLC). Methods: Patients with locally advanced NSCLC were treated with conventional fractionated radiotherapy or three dimensional conformal radiotherapy (3 DCRT), concurrently with a dose escalating schedule of paclitaxel. All patients were divided into three groups, A with paclitaxel $30mg/m^2$, B with paclitaxel $60mg/m^2$ and C with paclitaxel $90mg/m^2$. Paclitaxel was repeated every week for a total of 4 or 6 weeks. Results: Among 109 patients, response rates were 68.8%, 71.1% and 71.8% (p>0.05) for group A (n=32), B (n=38), and C (n=39) respectively. Accordingly, disease control rates were 81.3%, 81.6% and 82.1% (p>0.05). Progression-free survival time was $8.0{\pm}5.0$ months, $11.6{\pm}6.1$ months, and $14.8{\pm}7.9$ months (p<0.05), respectively. Overall survival time was $15.4{\pm}7.6$ months, $18.2{\pm}8.0$ months, and $22.0{\pm}7.6$ months (p<0.05), one-year survival rates were 62.5%, 73.1% and 90.0% (p>0.05) and two-year survival rates were 31.3%, 38.5% and 50.0% (p<0.05). Main side-effects were bone marrow suppression, radiation related esophagitis and gastrointestinal reaction. Conclusion: In treating patients with NSCLC, concurrent chemoradiotherapy with paclitaxel improves early response compared with conventional fractionated radiotherapy or 3 DCRT. The survival rate was improved with the addition of paclitaxel, but there was an increase in adverse reactions when the dose of paclitaxel was increased.

• Clean Technology
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• v.11 no.1
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• pp.41-50
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• 2005

In this study, semibatch emulsion copolymerization of n-BA as adhesive component and MMA as coagulant component were carried out for the stable acrylic polymer latex in aqueous phase for polymer cement using LE-type nonionic surfactant as environmental friendly surfactant. The stable polymer emulsion was obtained with the increases of chain length(n) of this surfactant. The effect on the amount of LE-50 as nonionic surfactant were showed that the concentration of polymer latex were increased by increasing the amount of LE-50, whereas the average particle size were decreased by increasing the amount. The addition of functional monomer in initial reactor charge showed a significant effect on the final polymer concentration and the latex particle size. The single polymerization of each n-BA or MMA showed a very low concentration of polymer latex and very big particle size due to coagulation. In the polymerization composed of mixed monomer with MMA and n-BA, the larger the ratio of MMA to n-BA in the copolymers, the greater the amount of coagulum produced. It was found that a stable copolymers were obtained in the range of 15-35 % of n-BA. Moreover, incorporation of some functional monomers in addition to of main monomers became more stable polymer latex. Through DSC and IR analysis, the final polymer latex was composed by MMA/n-BA/AA/AM with a single Tg depending on the reaction conditions. As a result, the conditions of this acrylic polymerization could also be effectively controlled to get the desired final products.

• Clean Technology
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• v.13 no.4
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• pp.287-292
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• 2007

[ $M/Al_2O_3$ ] (M = Mn, Fe, Co, Ni, Cu) catalysts supported on commercial alumina ($Al_2O_3$) were prepared by an impregnation method, and were applied to the hydrogen production by auto-thermal reforming of ethanol. It was revealed that each catalyst retained its own metallic phase and product distribution strongly depended on the identity of active metal. Among the catalysts prepared, $Ni/Al_2O_3$ and $Co/Al_2O_3$ showed the best catalytic performance in the auto-thermal reforming of ethanol. However, the reaction mechanisms over these two catalysts were different. Ni/Al_2O_3 catalyst showed 100% ethanol conversion at $500^{\circ}C$, but it exhibited a rapid decrease in hydrogen selectivity. Although $Co/Al_2O_3$ catalyst showed an excellent performance in hydrogen selectivity, on the other hand, no significant improvement in hydrogen yield was observed due to the low ethanol conversion over the catalyst.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.44 no.3
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• pp.343-347
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• 2018

We synthesized 1, 2-hexanediol galactoside (HD-Gal) from HD using Escherichia coli (E. coli) ${\beta}-galactosidase$ (${\beta}-gal$), in which the reaction is generally called as transgalactosylation (reverse hydrolysis). In this study, we investigated how much HD-Gal and HD had a cytotoxic effect on HaCaT cell, in order to compare HD-Gal with HD in terms of the cytotoxicity of human skin cell. Cell proliferation assay and phase-contrast microscope observation were used for investigating the cytotoxicity. As a result, HD-Gal had not cytotoxic effect on HaCaT cell in the concentration range from 42.2 to 211 mM. In addition, when we observed the cells using microscopy, there was no change in the cell morphology. Meanwhile, when 42.2 mM and 84.4 mM HD were treated on HaCaT cell, we did not observe the cytotoxicity; however, when 168.8 mM and 211 mM HD were on HaCaT cell, HD had a higher cytotoxic effect on HaCaT cell. In addition, when HD was treated on the cells regardless of the concentration of HD, there were obvious changes in cell morphology and cell number. It was expected hopefully that HD-Gal would be applicable as a substitute for HD as a less toxic preservative in views of safety, health, and well-being.

• Applied Chemistry for Engineering
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• v.5 no.1
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• pp.160-175
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• 1994

Fibrous potassium hexatitanate whisker with the size of $ID=0.5{\sim}1{\mu}m$ and length=$100{\sim}1000{\mu}m$ (aspect ratio=100~1000) was produced through the reaction between titanium dioxide and potassium carbonate using the slow-cooling calcination followed by water leaching treatment. The optimum condition for the production of fibrous potassium titanate was calcination temperature of $1100^{\circ}C$ for 5hrs, $TiO_2$ mole ratlo to $K_2CO_3$ of 4.5 and slow-cooling rate of $0.5^{\circ}C/min$ to $860^{\circ}C$. Fibrous crystal are grown by the association between the solid potassium titanate and liquid phase during the slow-cooling process. The Proper water leaching condition for removing of K component was leaching time of 10hrs in boiling water. Pressurizing of the mixture of $K_2CO_3$ and $TiO_2$ to be calcinated became effective on the growth of fibrous crystal.

• Science of Emotion and Sensibility
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• v.17 no.1
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• pp.105-114
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• 2014

The skin-tone in portrait photography is one of the most sensitive parts that need retouching by a photographer. To investigate the emotional reactions related to users' preferences for the skin-tone variations in portrait photography, two experiments were conducted. The first experiment included JND(Just Noticeable Difference) test to determine the general distribution of preferences with many photographs that varied in phases up to an extreme one, as a result, preferences for the brightest skin-tone and the red or magenta one were found. Based on the first experiment, we reduced the number of samples by adjusting their brightness to the brightest phase constantly. To intensify the second experiment, we reduced the number of the other colored samples to only one and made samples for five phases from green to magenta, namely the most preferred skin-tone in the first experiment. In the second experiment, the common preference for a neutral skin-tone and the partial difference between the two gender groups were found. In conclusion, the users' preference for a particular skin-tone was positively affected by emotions such as 'happiness' or 'comfortable'. With this investigation, we compiled some statistically meaningful facts to confirm that the preferences of the users depend positively on controlling the skin-tone in portrait photography.