• Journal of the Korean Ceramic Society
• /
• v.27 no.1
• /
• pp.109-117
• /
• 1990

Magnetite for Water-based ferrofluid was synthesized by air oxidation of aqueous suspension in the pH range 7-12 at $65^{\circ}C$. The optimum condition of magneite formation was delineated by examining various physicochemcial properties such as Fe2+ content, phase characteristics, MHC and $\sigma$max. The point of zero charge of iron oxide powders obtained at various pH conditions were correlated with the oxidation state of Fe in the iron oxide. The magnetite powder prepared at pH 9 ws dispersed using sodium oleate and sodium dodecylbenzenesulfonate (SDBS) as dispersants, and the dispersion characteristics of the magnetite ferrofluid were examined by means of the fraction of solid dispersed, zeta potential data and FT-IR spectrum. A simple calculation on the potential energy of two interacting magnetite particles showed that the dispersion stability was directly correlated with height of the potential energy barrier or the shape of zeta potential.

• Textile Coloration and Finishing
• /
• v.22 no.2
• /
• pp.88-93
• /
• 2010

Using extracted sepia melanin powder by repeated treatments with aqueous sodium hydroxide and acetic acid solutions, vat dyeing of wool and cotton fabrics was carried out under various dyeing conditions including concentration of melanin, alkali, reducing agent and salt, as well as dyeing time and temperature. A K/S of 25.3 for wool fabrics was obtained at the optimal dyeing condition with 9% owf melanin, 0.5g/L NaOH and 56g/L $Na_2S_2O_4$ without salt at $80^{\circ}C$ for 90minutes. The vat dyeing of sepia melanin was applicable to both cotton and wool fabrics but the wool showed higher dyeability. The color fastness properties of the dyed wool and cotton fabrics were excellent to washing, rubbing and light irradiation.

• The Korean Journal of Food And Nutrition
• /
• v.12 no.2
• /
• pp.119-123
• /
• 1999

Test of the optimum condition of solid phase micro extraction(SPME) was performed by use of 5 vol-atile components in dilute aqueous solution. Volatile components of Sancho(Zanthoxylum schinifolium) were isolated by SPME method and were analyzed by GC/MSD and compared with volatile compone-nts isolated by simultaneous distillation extraction (SDE) method. Total 31 components were identified by comparing gas chromatography retention time and mass spectral data. The major compounds were limonene geranyl acetate $\beta$-phellandrene phellandral mycene linalool rose oxide caproic acid and caprylic acid SPME sampling procedure was found to be a good method for qualitative analysis of the volatile components.

• Korean Journal of Poultry Science
• /
• v.26 no.2
• /
• pp.85-95
• /
• 1999

The mechanically deboned chicken meat(MDCM) has several limits in using for in using for in processed meat products as a main material because of poor color and textural properties, chance of microbial contamination and lipid oxidation. There has been a growing interest all over world in the application of MDCM to the surimi process. The surimi made from MDCM contains a high concentration of myofibrillar protein since this processing involves repeated washing processes with an aqueous solution in order to remove heme pigments, fat and other undesirable substances. The quality of the surimi made from MDCM is affected by various processing factors, such as kinds of wash solution, ion strength, washing cycle, temperature, pH changes, composition, part of muscle, particle size, and rigor state etc. A number of researchers havee investigated the effect of the various washing conditions on the properties of surimi gels. A fuller information of all the factors affecting surimi processing and gel formation by heat-induced gelation has not been known yet.

• Natural Product Sciences
• /
• v.22 no.4
• /
• pp.287-292
• /
• 2016

Aqueous extraction of Citrus unshiu peels (AECUP) is mainly comprised with pro-angiogenichesperidin and narirutin. In this study, we report approaches to increasing the yields of extracted hesperidin and narirutinfrom Citrus unshiu peels using proper solvents. Significantly improved yields of both compounds were obtained using methanol and dimethyl sulfoxide (DMSO) compared to acetonitrile, ethyl acetate, ethanol, and isopropyl alcohol. Especially, effect of DMSO was by far the better of the two solvents in extraction of hesperidin. In addition, the DMSO extracted hesperidin significantly induced the pro-angiogenic effects of human umbilical vein endothelial cells (HUVECs) and markedly up-regulated phosphorylation of the ERK1/2 signaling pathway. These results demonstrate that pro-angiogenic inducer; hesperidin and narirutin can be simply, easily, and effectively extracted from Citrus unshiu peels.

• Environmental Analysis Health and Toxicology
• /
• v.16 no.4
• /
• pp.143-151
• /
• 2001

Six rivers were selected as preliminary screening sites to determine the test conditions of Microtox in assessing the toxicity of the sediment. In addition, a pH range of 6.0∼6.5 was established in testing pore water, aqueous extracts and organic extracts. Each extractable fraction of sediment showed different toxicities. Therefore, in order to properly examine the toxicity in the sediment, all extractable fractions of sediment samples needed to be tested with Microtox. Thus, sediment samples were additionally collected from at least 4 secondary sites within 50∼100ｍ area of the primary sampling site to reduce any variation or deviation in toxicity assessment. From all sediment toxicity data that was collected from this study, it was concluded that the Keumho river was the most polluted with the highest sediment toxicity of all the rivers analyzed and needed further detailed research on its pollution problem.

• Journal of Powder Materials
• /
• v.12 no.4 s.51
• /
• pp.284-290
• /
• 2005

ZnO nanostructures with various shapes were synthesized under ambient pressure condition by a wet chemical reaction method. Nanorods of ZnO with hexagonal cross-section and their aggregates with radiate shape were synthesized. Precursor concentration affected considerably the shape evolution of ZnO nanorods. Low precursor concentration was proved to be more preferable to the growth of ZnO nanorods, which is attributed to the intrinsic characteristics of chemical reaction in the synthesis of ZnO from zinc compounds.

• Journal of the Korean Applied Science and Technology
• /
• v.24 no.3
• /
• pp.246-252
• /
• 2007

$BaTiO_3$ powders were prepared by sol-gel method from different concentration of KOH aqueous solution and Ba/Ti molar ratio. Particle shape, size and crystal structure of prepared $BaTiO_3$ powders were analyzed by SEM, XRD, and FT-IR. As the result of KOH concentration changing, spherical particles were obtained by condition more than 3 M and particle size decreased as concentration increasing. Different appearance showed between dried and sintered powders against changing of Ba/Ti molar ratio. In case of dried powders, the crystallinity decreased as molar ratio increasing. On the other hand, increased as molar ratio increasing in case of sintered powders.

• YAKHAK HOEJI
• /
• v.53 no.5
• /
• pp.235-240
• /
• 2009

The interaction of cadmium (II) ion with quercetin was investigated in aqueous solution at different pH. The quercetin/cadmium stochiometries for cadmium (II) binding have been determined by UV-vis spectrophotometric method. The complexation of Cd(II) ion with 54.72 ${\mu}M$ quercetin (A=1.00793) was formed in 0.2 M $NH_3-0.2$ M $NH_4Cl$ (pH 8.0) buffer solution. 1:1 Cd(II)-complex had a maximum absorbance and showed the bathochromic shift of the long-wavelength band of the UV-vis spectra in the alkaline pH when interacted with quercetin in buffer solution. These results suggest that Cd(II)-quercetin complex has the optimal condition of chelation in basic buffer solution.

• Journal of environmental and Sanitary engineering
• /
• v.22 no.1 s.63
• /
• pp.29-35
• /
• 2007

This study was examined adsorption ability of heavy metal Hg(I), Pb(II), and U(Vl) ion use of fruit from schizandra chinensis, The fruits of schizandra chinensis sample used breaking into fragments $50{\sim}100$ mesh. The sample solution was mixed fruits of schizandra chinensis and heavy metal ion. Each heavy metal ion of into solution was quantum analysis with ICP-AES. As the result, each condition of maxium adsorption ability of heavy metal ion was high in the range of pH 5-7, adsorption time was about 15 minutes, and the optimum temperature was $100^{\circ}C$. The heavy metal ion was increased adsorption in order of increasing concentration and in ethanol solution better than in aqueous solution.