• Korean Journal of Food Science and Technology
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• v.42 no.5
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• pp.565-570
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• 2010

A coenzyme Q10 nanoemulsion was prepared using high pressure homogenization with different valve type conditions (A, B, and C) and cycle numbers (1, 2, and 3). The particle size, transmittance, zeta potential, and coenzyme Q10 content of the prepared coenzyme Q10 nanoemulsion were measured. The stability of the prepared coenzyme Q10 nanoemulsion was evaluated on heating ($95^{\circ}C$), freezing ($-20^{\circ}C$), and different pH (2-10) conditions. Also, the prepared coenzyme Q10 nanoemulsion was stored at different temperatures of 4, 25, and $40^{\circ}C$ for 12 weeks to evaluate its storage stability. In this study, the optimal conditions of high pressure homogenization for the preparation of a coenzyme Q10 nanoemulsion were identified to be 150 MPa, C valve, and a cycle number of 3. The results showed that the prepared coenzyme Q10 nanoemulsion had an average particle size of 40 nm, generated no deposits or floating matter when stored at either 4 or $25^{\circ}C$ for 12 weeks, and displayed excellent dispersibility and transparency when processed at different pHs (4-10) or heating ($95^{\circ}C$) and, freezing ($-20^{\circ}C$) conditions. Our results indicated that a coenzyme Q10 nanoemulsion prepared by high pressure homogenization can be used for preparing beverages in the food industry.

• Applied Chemistry for Engineering
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• v.17 no.1
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• pp.52-57
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• 2006

Coptidis Rhizoma, an antimicrobial agent from natural source, is known to have the antiviral effect on the Candida albicans that causes the infectious dermatitis. The valuable protein was extracted from the Coptidis Rhizoma, To prevent denaturalization from external stimulus and improve adsorption onto the skin, the nano-sized liposomes were prepared as a carrier. The CPR-containing liposomes showed an average diameter of 187 nm, surface charge of 3.337 mV and 33% encapsulation efficiency. The release behavior of CRP from the liposome was investigated with various temperature and releasing time. The PVA solution was coated on the surface of liposome to improve the stability. The coated liposome showed slow release behavior in comparison with the non-coated liposome. The CRP in the liposome maintained the effect on the Candida albicans after treating it at 50 and with ultraviolet for 24 h.

• Clean Technology
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• v.10 no.2
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• pp.61-72
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• 2004

In this study, aqueous/semi-aqueous cleaning agents which consist of organic solvent, surfactant, cosurfactant, and water were developed by changing formulation parameters such as organic solvent type and contents, surfactant type and contents, and cosurfactant/surfactant(A/S) ratio, etc.. And physical properties and flux removal of the formulated cleaning agents have been evaluated. Also, the performance of oil-water separation from the rinse water contaminated during the cleaning process was evaluated for its recycling. The formulated cleaning agents in this work expected to have good penetration because of their low viscosity and low surface tension values of 30.2~32.5 dyne/cm. The flux removal with the terpene type cleaning agent was higher than that with hydrocarbon type cleaning agent and two commercial products (CPA(commercial product A), CPB(commercial product B)). And the performance of oil-water separation by gravity settling from the rinse water contaminated with formulated cleaning agent and soils was shown to be very good. The cleaning agents developed in this work were applied to surface mounting technology(SMT) cleaning process for manufacturing electronic parts at L electronic company. As a result, the newly developed cleaning agents showed two times better cleaning speed for removal of solder cream than the conventional ond containing ethanol and IPA(isopropyl alcohol). In addition, malodor and VOC problems generated by the previous organic cleaning agents have been solved in the manufacturing field through introduction of the non-volatile and environmental-friendly cleaning agents to the field.

• Korean Journal of Agricultural Science
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• v.22 no.2
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• pp.151-155
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• 1995

Two types of modified celluloses which contain trinitrophenyl groups as chromophore were synthesized from carboxymethyl cellulose Whatman CM 70 and CM 32. Diaminoethyl groups were added to the CM 70 and CM 32 to make DAE-CM celluloses and then the DAE-CM groups were substituted by 2,4,6-trinitrophenyl groups to produce TNP-celluloses. Average particle size of the TNP-cellulose from CM 32 was $44.6{\pm}9.6{\mu}m$ in diameter and $127.9{\pm}22.5{\mu}m$ in length, which was much smaller than those from CM 70, however its TNP-moiety per gram determined by using the molar extinction coefficient $1.33{\times}10^4$ of ${\varepsilon}$-TNP-lysine at 345 nm, was 0.68 millimoles, which was 5.6-fold greater than those from CM 70. The absorption spectrum of TNP-oligosaccharides which were the soluble products of TNP-celluloses by a cellulase preparation Onozuka R-10, showed a maximal peak at 344 nm. Increases in the absorbance during hydrolysis were linear with the enzyme concentration, and the differences of slope values between two types of TNP-celluloses that the more semsitive assay could be achieved by using those from CM 32 as substrate at the low range of the enzyme concentration.

• Journal of the Korean Magnetics Society
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• v.11 no.1
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• pp.21-25
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• 2001

$\alpha$-Fe$_2$O$_3$ thin films were prepared on Si substrate by a pulsed laser deposition system and characterized by X-ray and Mossbauer spectroscopy. The appropriate conditions of pulsation was the power of 5.128 W/cm2 at on oxygen pressure of 0.1 Torr at a substrate temperature of 30$0^{\circ}C$. After that the film was heated at 80$0^{\circ}C$ for 1 day. The particles shape deposited on the film was ellipsoidal and the average length and width were 200~300 nm, 70~150 am respectively. The crystal structure was conformed to be of corundums symmetry with the hexagonal unit cell having a lattice constant of u = 5.03$\pm$0.05 $\AA$, c = 13.735$\pm$0.05 $\AA$. The average angles between the atomic spin and the magnetic hyperfine field of Fe ion were 38$^{\circ}$and 48$^{\circ}$ at above and blow the Morin transition temperature respectively. The Morin transition was found to occur at the temperature ranges from 200 K to room temperature and atomic spin direction was assumed to change from 48$^{\circ}$ to 80$^{\circ}$in respect to the c-axis.

• Korean Journal of Food Science and Technology
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• v.29 no.5
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• pp.888-894
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• 1997

Two hulled and two hull-less barley varieties were investigated for ${\beta}-glucan$ enrichment. Hull-less barleys contained higher levels of total ${\beta}-glucan$ than hulled barleys, and were thus suitable as starting materials for preparing ${\beta}-glucan-rich$ fractions. Particularly, a waxy type (Suweon-291) of hull-less barley was found to have high soluble dietary fiber content containing primarily ${\beta}-glucan$, compared to the other non-waxy barley varieties. ${\beta}-Glucan$ content of barley during pearling process was measured, and the highest value was observed at the pearling yield of approximately $70{\sim}75%$. The pearled barley grains were ground and sieved to yield ${\beta}-Glucan$ enriched fractions containing up to 22% ${\beta}-glucan$. In the meanwhile, whole barley samples were directly milled by $B{\ddot{u}}hler$ mill to produce bran, shorts, break flour and reduction flour. ${\beta}-Glucan$ contents in the bran and shorts from the milled stream were relatively high, and further concentration of ${\beta}-glucan$ could be accomplished by successive sieving of the bran and shorts fractions. Pearled barley and milled stream could be used to prepare barley fractions with ${\beta}-glucan$ concentrations $2.4{\sim}3.1$ times those of the original barley grain. Water solubility of barley ${\beta}-glucan$ from pearled barley and the milled stream was in the range of $40{\sim}81%$.

• Journal of Korean Society of Environmental Engineers
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• v.37 no.5
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• pp.277-284
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• 2015

In order to analyze the contamination level of sediment samples taken from Chusori and Chudong areas in Daechung Reservoir, the particle size and concentrations of organics and nutrients were analyzed and phosphorus fractionation analysis was conducted. The average fraction of silt-sized particles was 92% in the sediments taken from Chudong area and Chusori area at the site adjacent to main current, which was higher than that from the upper Chusori area. The concentrations of total phosphorus in the sediments at Chusori and Chudong area were 999 (${\pm}98$) and 1,123 (${\pm}119$) mg/kg sediment, respectively. The fractions of autochthonous phosphorus, which can be readily eluted by change of environmental conditions, were much higher than those of allochthonous phosphorus, indicating the internal load can contribute the eutrophication in these areas. The concentrations of total nitrogen were over 5,600 mg/kg sediment in all samples, which is the guideline of Contamination Assessment of River and Lake Sediments of the Ministry of Environment, indicating the contamination level of total nitrogen is serious in the sediments. It is concluded that the countermeasures to manage the quality of sediments are required to improve the water quality in the Daechung Reservoir.

• Food Science and Preservation
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• v.21 no.2
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• pp.181-186
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• 2014

This study was conducted to that investigate the quality characteristics of wet-ground whole-grain buckwheat powder for the buckwheat husk. The particle size of buckwheat rice was 74.84 ${\mu}m$, which was approximately four to five times larger than wet-ground whole buckwheat by wet grinding. The particle size showed that there was no significant difference after 90 min on wet grinding. The total phenolics and total flavonoids contents of the whole buckwheat powder were higher than those of buckwheat rice, and they gradually increased wet grinding progressed. The rutin contents of the buckwheat increased after wet grinding and was 152.90 ppm at 90 min. There was no significant difference in the quercetin contents after wet grinding at different times. The mineral contents (Ca, K and Mg) of the whole buckwheat powder were greater than those of the buckwheat rice. Further, Zn and Mn were detected in the whole buckwheat powder. The total amino acid content of the whole buckwheat powder increased to 22.27 mg%, and the important glutamic acid increased from 14.58 to 30.45 mg%. These study results were based on 90 min wet-grinding time for whole-buckwheat-powder manufacture. Whole buckwheat powder manufactured through wet grinding can be used as an active ingredient of buckwheat husk.

• Journal of the Korean Society of Food Science and Nutrition
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• v.21 no.1
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• pp.101-108
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• 1992

Changes were evaluated in chemical and textural properties of Jeung-pyun (fermented rice cake) altered by the particle size of rice flour, amount of added Tak-ju (Korean traditional unrefined liquor) and sucrose, fermentation time and temperature, and steaming time. Particle size of polished rice flour did not affect the volume expansion during fermentation of rice dough by Tak-ju. The maximum expanded volume was noted in the dough, containing 20% sucrose (rice flour vs sucrose = 5 : 1, w/w), fermented at $35^{\circ}C$ for 3 hours. Any volume expansion was not occurred in rice dough without sucrose. The highest value of reducing power and gelatinization degree were observed in the rice dough with Tak-ju (rice flour vs Tak-ju = 2 : 1, w/v), while the lowest blue value was revealed in that case. Steaming followed after fermentation made the smaller volume of bulk by $45{\sim}50%$ of the initial volume be showed just after fermentation. Jeung-pyun prepared under the conditions could give maximum expanded volume by fermentation showed the best overall quality by sensory and textual properties.

• Journal of the Korean Magnetics Society
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• v.18 no.3
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• pp.120-125
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• 2008

In this study, NiCoZn ferrites with the variation of sintering temperature and chemical composition were prepared by the coprecipitation. Microstructures Crystal structure of NiCoZn ferrites were analyzed by XRD and their electric magnetic characteristics were analyzed by LCR meter and their morphology observed by SEM. We identified that these powders have a typical NiCoZn spinel structure and nanoparticles average size of 40 nm. The impurity, the initial permeability and the Q factor value are the lowest of sintered NiCoZn ferrite at $1250^{\circ}C$. Also, we measured S-parameter for $(Ni_{0.4}Co_{0.1}Zn_{0.5})Fe_2O_4$ which showed a maximum reflection loss of -3.1 dB at 6 GHz for the 2 mm thick sample. From this result, we found that the NiCoZn ferrite can be used in ferrite microwave-absorbing application at a higher frequency region (> 6 GHz).