• Clean Technology
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• v.16 no.3
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• pp.172-181
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• 2010

Hydrofluoroethers (HFEs) with fluoride molecules in their structure which are evaluated as the third generation replacement alternatives to chlorofluorocarbons (CFCs) are known to be excellent for removal of nanoparticles and fluoride-type soils due to their low surface tension and high wetting index. In addition, HFEs have good physical properties with no flash point and excellent drying characteristics. But, HFEs also have shortcomings in that they are not effective for removal of organic soils due to their poor solubility in soil. In this study, $C_5$ HFE-based cleaning agents were formulated through addition of solvents such as isopropyl alcohol (IPA), ethyleneglycol monoether (EG), propyleneglycol monoethylether (PM) to HFE-7100 [$CF_3CF_2CF_2CF_2OCH_3$] or HFE-mec-f [$CF_3CHF=CF_2OCH_2CF_3$] with its maximum amount, respectively, in order to have no flash point for the safety in the working environment. These solvents are known to be excellent for dissolving organics in soil. Their physical properties and cleaning abilities for fluxes, water-insoluble cutting oils, and fluoride-type oils were evaluated and compared with those of other cleaning agents with single components. The experimental results show that the HFE-based formulated cleaning agents have various good physical properties which are almost similar to those of a single type of HFE cleaner. They show excellent cleaning ability for fluxes, water-insoluble cutting oils, and fluoride-type oils. These results indicate that the HFE-based formulated cleaning agents can be applicable to various industrial cleaning fields because of their good physical properties and cleaning abilities for various soils.

• Journal of Korean Society of Environmental Engineers
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• v.22 no.1
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• pp.61-71
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• 2000

When irradiate the power ultrasound into the aqueous solutions, water vapor is decomposed by the heat of very high temperature in the cavitation bubble to produce OH (hydroxyl radical) and H (hydrogen radical), and these radicals play a role in decomposing the substances in aqueous solution by oxidation and/or reduction, and in producing the hydrogen peroxide. Accordingly it is possible to predict that the quantity of hydrogen peroxide produced may correlate with the sonolysis mechanism of the substance in aqueous solution. Thus to confirm this prediction, the quantities of hydrogen peroxide produced from each of the air saturated distilled water and three aqueous solutions of TCE, benzene, and 2,4-DCP that are prepared by dissolving them into distilled water are measured. As a result, it showed that the quantity of hydrogen peroxide produced from the distilled water and three aqueous solutions are increased in order of distilled water>TCE solution>2,4-DCP solution>benzene solution, and decrease with decrease in concentration of organic substance, which coincide with the sonolysis mechanisms reported that TCE in aqueous solution is decomposed directly by the pyrolysis in and around the cavitation bubbles when its concentration is high and by the radical reaction when low, however, benzene and 2,4-DCP are decomposed not only by the pyrolysis but also by the radical reactions. Effects of such experimental parameters as the acoustic frequency and power and as the concentration showed that the higher the acoustic frequency and the lower the acoustic power, the less the quantity of hydrogen peroxide was produced. This result coincide with the theory of ultrasound for the relation between the cavitation that is the energy source of the power ultrasound in aqueous solution and these experimental parameters.

• The Korea Journal of Herbology
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• v.23 no.2
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• pp.59-65
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• 2008

Objectives : HRHDT has been known as a useful prescription with antibiotic, anti-inflammatory, antioxidative and immunosuppressive activity. To evaluate anti-atopic dermatitis effect of HRHDT, we treated HRHDT in NC/Nga mice model skin induced contact hypersensitivity. Methods : Contact hypersensitivity, a local inflammatory response of skin, was induced by spreading the back skin of NC/Nga mice with 0.4${\sim}$1% DNCB. HRHDT was prepared by dissolving 3% HRHDT in solution and treated 3 weeks on the back skin. Results : HRHDT significantly reduced TEWL and erythema by 0.4${\sim}$1% of DNCB treatment compared to control group. HRHDT also reduced IgE on serum obtained from blood of DNCB-treated mice. Conclusions : These results showed that HRHDT could be used as a pharmaceutical material with anti-atopic dermatitis effect by reducing IgE in contact, hypersensitivity atopic dermatitis NC/Nga mice model by DNCB.

• Journal of Animal Science and Technology
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• v.58 no.8
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• pp.30.1-30.12
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• 2016

Background: The effect of choline chloride supplementation through forced drinking combined with concentrate diets containing Ca-fish oil on milk production and milk composition of Etawah Grade goats was evaluated. Choline chloride is an essential component in ruminant diets as it is required for fat metabolism. Method: The experiment was conducted in a completely randomized block design with three types of treatments and eight replications. The trial had two successive experimental periods; the first, during the eight weeks of late pregnancy, and the second, during the first 12 weeks of lactation. Twenty-four Etawah Grade does in the second gestation period were divided into three treatment groups. Commercial choline chloride 60 % in corncobs-based powder was used as a source of choline chloride. The treatments were no supplementation (control) and supplemented with either 4 g or 8 g/2days of choline chloride. Choline chloride was given to the animals through a forced drinking technique, after dissolving it in 60 ml drinking water. The initial body weight of does was $38.81{\pm}3.66kg$. The does were penned individually, and were given fresh chopped King Grass ad libitum and 700 g/day of concentrate diets containing Ca-fish oil, starting eight weeks prior to expecting kidding and continuing for 12 weeks of parturition. Results: All nutrient intakes were not significantly different (p > 0.05) among the treatments during the late pregnancy and the lactation periods. Supplementation did not affect (p > 0.05) the average daily gains and feed conversion ratio during pregnancy but gave effects (p < 0.05) on the average daily gains, feed conversion ratio and income over feed cost during lactation. The highest average daily milk yields and 4 % fat corrected milk yields were found in goats supplemented with 4 g/2days of choline chloride and increased by 17.00 % and 24.67 %, respectively, compared to the control. Moreover, milk composition percentage and milk constituent yields improved significantly (p < 0.05) in those supplemented with 4 g/2days of choline chloride. Conclusion: The supplementation of 4 g/2days of choline chloride through forced drinking increased milk yields, the 4 % fat corrected milk yields, milk composition, milk constituent yields, and improved feed conversion ratio and income over feed cost of Etawah Grade goats.

• Journal of the Korean Electrochemical Society
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• v.6 no.2
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• pp.145-152
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• 2003

Capacitance of a hybrid capacitor that has characteristics of both electrolyte capacitor and supercapacitor is determined by anode surface covered with oxide layer. In this study, optimal condition processes for anode to fabricate a high voltage hybrid capacitor was investigated. We mixed aluminum powder having mean particle size of $40{\mu}m$ with NaCl powders at weight ratio of 4 : 1 and prepared a disk type electrode after annealing at various temperature. After dissolving NaCl in $50^{\circ}C$ distilled water, heat treatment, eletropolishing, chemical treatment, and the first and the second etching of Al disk were conducted. In each process, capacitances and resistances of the disk measured by ac-impedance analyzer were compared to find its optimum treatment condition. Also, the surface morphology of treated disks were observed and compared by SEM. After the second etching, the Al disk was anodized at 365V to make an anode of hybrid supercapacitor that can be operated at 300V, Capacitance and resistance of the anodized Al disk electrode was compared with those of commercialized conventional aluminum electrolytic capacitor at different frequencies.

• Korean Journal of Food Science and Technology
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• v.26 no.6
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• pp.665-669
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• 1994

A rapid gas chromatographic (GC) profiling method was applied to dairy products (milk and cheeses) for the simultaneous analysis of volatile and nonvolatile organic acids. Cheese samples were first made into aqueous samples by dissolving in water. The aqueous samples were then extracted with organic solvents after the acidification and NaCI saturation. The organic layers (diethyl ether : hexane= 1 : 1) were extracted with $NaHCO_3$ saturated solution with subsequent solid-phase extraction of the aqueous phases using Chromosorb P column/diethyl ether followed by triethylamine treatment. The resulting triethylammonium salts of acids were directly converted into volatile tert.-butyldimethylsilyl derivatives, which were analyzed by dual-capillary column GC, and GC-mass spectrometry. From milk and four cheese samples studied, 31 organic acids including 21 fatty acids and other hydroxy and dioic acids were tentatively identified. The amounts of the fatty acids were different among the kinds of cheese and thus the simplified retention index (RI) spectra of organic acids were useful for the visual pattern recognition of each sample, when the Direct Comparision method between cheese and a blind sample were attempted, it was quickly recognized to be a gouda cheese with the 999 ppt match quality value.

• Journal of Conservation Science
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• v.32 no.2
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• pp.249-259
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• 2016

Effect of the flame retardants on Dancheong is studied in the present work. Two kinds of flame retardants were applied on Dancheong specimens and compared with control groups on which distilled water was applied instead of the flame retardants. The flame retardants enhanced the hygroscopic property of the surface of Dancheong. Furthermore, the added flame retardants reacted with oyster shell white($CaCO_3$) and lead red($Pb_3O_4$), producing new chemical compounds like Calcium phosphate tribasic and Lead Phosphates which make the painted layer of Dancheong dissolving and whitening over certain period of time. When applied in excessive amount and exposed in repetitive wet and dry condition, especially, they aggravate the surface problems significantly. These results will provide a good reference on the study of the discoloring/whitening effect of Dancheong layers at many traditional wooden building in Korea.

• Journal of the Korean Applied Science and Technology
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• v.37 no.4
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• pp.744-754
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• 2020

We investigated the whether endurance exercise and MitoQ intake mediated neuroprotection are associated with mitochondrial function in 1-methyl-4-phenyl-1,2,3,6 tetrahydropyridine(MPTP) -induced mice model of Parkinson's disease. C57BL/6 male mice were randomly assigned to five groups: Normal Conrol(NC, n=10), MPTP Control(MC, n=10), MPTP +MitoQ(MQ, n=10), MPTP + Exercise(ME, n=10) and MPTP + MitoQ + Exercise(MQE, n=10). Exercise intervention groups performed the treadmill exercise for 5days/week for 5 weeks with gradual increase of intensity. MitoQ intake groups consumed the MitoQ at a concentration of 250μmol by dissolving with water during experiment period. Our data demonstrated that ME and MQE group restored MPTP-induced motor dysfunction. In addition, treatment groups(MQ, ME and MQE) increased tyrosine hydroxylase levels, and suppressed the accumulation of α-synuclein levels. Futhermore, treatment groups modulated the mitochondrial function such as upregulated mitochondrial biogenesis, increased antioxidant enzyme, enhanced a anti-apoptotic protein(e.g., BCL2), and reduced a pro-apoptotic protein(e.g., BAX). Taken together, these results suggested that endurance exercise and MitoQ intake-mediated increase in mitochondrial function contributes to improvement of aggravated dopaminergic neuronal, resulting in attenuation of motor function of Parkinson's disease.

• The Korean Journal of Physiology
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• v.4 no.2
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• pp.1-4
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• 1970

A study was planned to see if the Panax Ginseng has any influence upon the body weight of young rats. Thirty-two male an4 an equal number of female rats were used, whose body weight at the experiment ranged from 35 to 40 gm. The male as well as the female rats were divided into the ginseng and the saline groups of 16 rats each. For 54 consecutive days animals belonging to ginseng and the saline groups received every day 0.5 ml Per 100gm body weight of ginseng extract and an equal amount of saline, respectively, and had eir body weight measured every 3rd day. The ginseng extract was prepared by seething 300 gm of Korean Panax Ginseng with 95% ethyl alcohol on a boiling water bath for about 300 hr and dissolving 4 mg of the yield (52.2gm of dark brown substance) in 1 ml of saline. Results obtained were as follows: 1. For about 30 days from the beginning of drug administration, the body weight of both the male and female rats belonging to the ginseng groups did not differ significantly from that of the saline groups. 2. From around the 30th experimental day (body weight: about 130 gm) on, however, both the male and female rats receiving ginseng gained in body weight significantly more than the saline-group animals of both sexes did. 3. In the latter period, male rats of the ginseng as well as the saline groups, but especially the ginseng male animals, picked up significantly more weight compared with the female rats. It is concluded from the above results that in rats the ginseng helps gain in body weight regardless of sex.

• Korean Chemical Engineering Research
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• v.52 no.4
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• pp.436-442
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• 2014

In this study, we developed an optical-fiber sensor using cobalt chloride solution to monitor temperature in real-time between long distance points unaffected by the electro-magnetic wave and the vibration. Cobalt chloride solutions were made using 10% water and 90% ethanol (v/v) solution. The transmittance of these solutions was analyzed on 655 nm using UV-Visible spectrometer regarding temperature change. Also 30.8 mM cobalt chloride solution was gelled by dissolving polyvinyl butyral and the transmittance of this was analyzed on 655 nm regarding temperature change. The results of transmittance and optical power measurement showed decrease of both transmittance and optical power with increase of temperature from 66.8% and 149.5 nW at $25^{\circ}C$ to 7.1% and 48 nW at $70^{\circ}C$, respectively. These results support the possibility of gelled cobalt chloride/polyvinyl butyral as an optical-fiber sensor to monitor temperature change.