• Journal of Environmental Science International
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• v.25 no.4
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• pp.567-577
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• 2016

The purpose of this study was to measure the antioxidant activity and bioactivity of black chokeberry (Aronia melanocarpa). The black chokeberry was known to contain many physiologically active substance, such as ascorbic acid, anthocyanin, quercetin. We extracted black chokeberry powder from four solvents such as chloroform:methanol(CM, 2:1, v/v), distilled water (DW), 70% ethanol, 70% methanol. After that, we determined anthocyanin, total phenol, flavonoid content, DPPH radical scavenging activity, ABTS radical scavenging activity, ferric reducing antioxidant power, reducing power and Nitrite scavenging activity of black chokeberry extracts and as results of comparing each extract. respectively. From the above results shows that antioxidant activity and bioactivity of black chokeberry extracts was the highest in 70% methanol (p<0.05). The results suggest that black chokeberry can be used as nutraceutical foods and natural antioxidant.

• Korean Journal of Materials Research
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• v.27 no.2
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• pp.63-68
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• 2017

A black nickel oxide powder, one of the commercial nickel oxide ores, was reduced by hydrogen gas in a batch-type fluidized-bed reactor in a temperature range of 350 to $500^{\circ}C$ and in a residence time range of 5 to 120 min. The hydrogen reduction behavior of the black nickel oxide was found to be somewhat different from that of green nickel oxide ore. For the black nickel oxide, the maximum temperature (below which nickel oxide particles can be reduced without any agglomeration) was significantly lower than that observed for the green nickel oxide. In addition, the best curve fittings of the Avrami model were obtained at higher values of the overall rate constant "k" and at lower values of the exponent "m", compared to those values for the green nickel oxide. It may be inferred from these results that the hydrogen reduction rate of the black nickel oxide is faster than that of the green nickel oxide in the early stages, but the situation reverses in the later stages. For the black nickel oxide ore, in spite of the low temperature sintering, it was possible to achieve a high degree fluidized-bed reduction at lower temperatures and at lower gas consumption rates than was possible for the green nickel oxide. In this regard, the use of black nickel oxide is expected to yield a benefit if its ore price is sufficiently lower than that of the green nickel oxide.

• Proceedings of the KIEE Conference
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• 2009.07a
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• pp.1328_1329
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• 2009

Nano porous indium tin oxide (ITO) powder was synthesized employing a new route sol-gel combustion hybrid method using Ketjen Black as a fuel. The nano porous ITO powder was composed of $SnCl_4$-98.0% and $In(NO_3)_3{\cdot}XH_2O$-99.999%, produce with a $NH_4OH$ with sol-gel method as a catalyst [1,2]. Crystal structures were examined by powder X-ray diffraction (XRD), and those results show shaper intensity peak at $25.6^{\circ}(2{\Theta})$ of $SnO_2$ by increased sintering temperature. A particle morphology as well as crystal size was investigated by scanning electron microscopy(FE-SEM), and the size of the nano porous powder was found to be in the range of 20~30nm. ITO films could controlled by nano porous powder at various sintering temperature in this paper[3,4]. The sol-gel combustion method was offered simple and effective route for the synthesis of nano porous ITO powder[5].

• Transactions of the Korean hydrogen and new energy society
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• v.22 no.4
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• pp.504-511
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• 2011

Nano-sized Sn powder was prepared by pulsed wire evaporation method. The Sn powder and carbon black were charged in jar and ball milled. The milling time was varied with 10 min., 1h, 2h, and 4h, respectively. The milled powders were dried and the shape and size were observed by FE-SEM. Nano-sized Sn powders were plastic-deformed and agglomerated by impact force of balls and heat generated during the SPEX milling. The agglomerated Sn powder also consisted of many nano-sized particles. Initial discharge capacities of milled Sn electrode powders with carbon powder were milled for 10 min., 1h, 2h, and 4h were 787, 829, 827, and 816 mAh/g, respectively. After 5 cycle, discharge capacities of Sn electrode powders with carbon powder milled for 10 min., 1h, 2h, and 4h decreased as 271, 331, 351, and 287 mAh/g, respectively. Because Sn electrode powders milled for 2h constist of uniform and fine size, the cyclability of coin cell made of this powders is better than others.

• Journal of the Korean Professional Engineers Association
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• v.12 no.1
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• pp.12-20
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• 1979

The early history of gun powder (black powder) and explosives was closely connected with the discovery of methods of preparing and purifing salpetre (potassium nitrate KNO$_3$). The Chineses apparently became acquainted with salpetre firstly on about 11th century, and they were possibly the original discoverers of salpetre for raw material of gun powder. The Egyptians called it “Chinese snow”, and it is significant that Chingis-Khan, the Mongol conqueror, took the Chinese eenginees with him in 1218 to use it for attacking the fortifications of the Persian cities. The black powder was invented by chance by Chinese alchemists during the Song dynasty (11th century) in the process of manufacturing medicine, and the powder was introduced to Europe by Mongol army. The manufacturing method of salpetre and gun powder was introduced to Korea from China in 1374, and the powder alld gunnery manufacturing project was developed by Mu Sun Choe(崔茂宣), the first Korean engineer late in Koryo dynasty. Coming in to Yi dynasty the explosive technic, extractive method of salpetre, and gunnery manufacturing process were developed greatly by Mu Sun Choe and Hai Sin Choe (崔海臣). However, confronting with the Japanes invasion at Imjin War (1597) with more powerful western style rifles which had been introduced from the Portuguese, on the contrary Korean army with the traditional guns couldn't compete with them. The Chochong(烏銃, the western rifle introduced in Japane) were much superior to the Chinese style traditional guns in the shooting power and striking efficiency. On the other hand, the Japanese battle ships armed only with the Chochong, when confronted with the Korean turtle shaped ships under the commanding of Admiral Yi Sun-Sin(李舞臣), were defeated by the Korean canons on the ships. The technical development of the modern powder industry in Korea. with the construction of four big explosive plants from 1930 to 1945, has resulted the mass-production of explosives. This study was purposed to investigate to the process with regard to the details of introduction to the explosive technology in Korea, and intended to give a help to the engineers who are engaged in study of the explosive technics by means of giving a spot light data on the early process of the designs, and making suggestion to the researchers for further study and invent a new and modern explosive.

• Analytical Science and Technology
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• v.21 no.3
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• pp.222-228
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• 2008

On living skin the chances of a successfully developing latent fingerprint are very limited. This is due to the fact that continual perspiration and rapid absorption diffuse into the lipophillic layer on skin. A study was conducted to investigate effectively developing method of latent fingerprints on human skin surfaces and pig skin likely corpse's skin. We used commercial fingerprint powder, black powders, black magnetic powder, fluorescence magnetic powder, Cyanoacrylate fuming (CA) and direct lifting methods (lifting paper, glasses and photo glossy paper). Developing of fresh fingerprints on living skin was achieved with S-powderblack, CA fuming and CA fuming following S-powder, fluorescence powder. The other powder tends to overwhelm the latent print and the background. But, latent fingerprint residue was disappeared with time after deposit on a living surface. In case of pig skin likely corpse's skin, latent fingerprint detection was achieved with CA fuming following S-powder and deposited print during 6 hr at $25^{\circ}C$, 40% relative moisture yielded excellent fingerprints with clear ridge details using 1 min CA fuming. And enhancement of fingerprint detection image using forensic light source was achieved.

• Journal of the Korean Electrochemical Society
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• v.17 no.1
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• pp.57-64
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• 2014

Carbon electrodes for capacitive deionization were fabricated through mixing two different carbon powders (activated carbon powder, carbon black) with different particle sizes to investigate physical or electrochemical properties and finally desalination performances of the electrodes with various compositions of two carbon powders in weight and were compared with the electrode consisting of activated carbon. As a result, the electrode structure became more packed as increasing the amount of carbon black and resulted in 10% increase in mesopore fraction. The specific capacitance obtained from cyclic voltammograms of various electrodes showed that the electrode containing carbon black only had 107.4 F/g, while the specific capacitance of the electrode having more amount of carbon black increased and was higher than the one having no carbon black. The results of desalination runs in a capacitive deionization cell exhibited that the electrode having the highest amount of carbon black (1 wt%) in this study had the highest desalting efficiency, and no significant pH variation was observed during the runs. It was analyzed using accumulated charge that the fraction of non-Faraday current increased as the amount of carbon black increased in the electrodes. It can be concluded that the addition of carbon black changed the electrode structure resulting in an increase in the fraction of mesopore and finally enhanced the desalting efficiency by decreasing Faraday current.

• Journal of the Korean Society of Food Culture
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• v.29 no.1
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• pp.91-100
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• 2014

This study investigated the antioxidative activities and quality characteristics of gruel as a home meal replacement with Angelica keiskei powder pre-treated by far-infrared radiation or freeze-drying methods. Far-infrared treated Angelica keiskei powder (F-IAP) showed significantly lighter, weaker green, and stronger yellow color values than powder subjected to freezedrying (FAP) (p<0.001). F-IAP showed higher total phenolic compound contents than that of the FAP. ABTS radical scavenging activity of F-IAP was 50.31%, which was significantly higher than that of FAP, at 43.51% (p<0.05). Color values of gruel significantly decreased with increased addition of Angelica keiskei powder (p<0.05). Gruels containing far-infrared treated Angelica keiskei powder (F-IAG) showed higher total phenolic compound contents as well as ABTS radical scavenging activities compared to the gruels containing freeze-dried Angelica keiskei powder (FAG). Gruels containing 5 g of Angelica keiskei powder showed 2.0 to 2.5 times higher antioxidant activities than those containing powder alone due to the presence of other ingredients with antioxidant activities such as black soybean or sweet pumpkin. In the results of sensory evaluation, F-IAG containing more than 5 g of Angelica keiskei powder had higher sweetness and roasted grain flavor, as well as lower bitterness and astringency compared to FAG. Sensory acceptance tests of all samples showed higher scores than 5.0 representing possibilities of successful development of gruels as a home meal replacement containing Angelica keiskei powder.

• Food Science of Animal Resources
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• v.31 no.2
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• pp.224-231
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• 2011

This study was conducted to investigate the effect of peppermint powder on meat quality and fatty acid composition in finishing Korean native black pigs. Ninety pigs were randomly allocated to three dietary treatments and fed peppermint powder at 0 (C), 0.2 (T1), and 0.4% (T2) in the basal diet, respectively for 50 d. The proximate composition of Longissimus dorsi muscle was not significantly different among the treatments; however, the fat content in T2 tended to be lower than the control. No difference in $pH_{45min}$ was observed, whereas $pH_{24h}$ was higher in T2 than the control (p<0.01). T2 showed the lowest lightness (p<0.01) and yellowness values (p<0.05), but shear force and drip loss were no different among the treatments. Individual fatty acid and cholesterol compositions did not differ among the treatments; however, T1 showed a decreasing trend for saturated fatty acid content and an increasing trend for unsaturated fatty acid content. The hypocholesterolemic index was significantly higher in T1 than in the control (p<0.05). These results suggest that dietary peppermint could positively affect fatty acid and cholesterol levels without changing meat quality in finishing Korean native black pigs.

• Economic and Environmental Geology
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• v.47 no.4
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• pp.455-466
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• 2014

We investigated reservoir properties of coalbed methane and typical development of drilling, completion, and stimulation methods. We optimized selection technique for development methods by consifering characteristics of coalbed methane resercoir in the San Juan, Black Warrior and Powder River basins of United States. Finally, well-optimized development methods for coalbed methane in the Barito Basin, Indonesia are suggested. This study may be useful to select economical and efficient drilling, completion, and stimulation methods in coalbed methane development especially in Indonesia.