• Korean Journal of Microbiology
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• v.45 no.1
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• pp.63-68
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• 2009

The exo-polysaccharide producing microorganism, Aureobasidium pullulans IMS-822, was isolated and identified from soil. The viscosity-average molecular weight of exo-polysaccharide was calculated as $8.9{\times}10^5$ by Mark-Houwink equation. The sugar component of exo-polysaccharide was determined as glucose by HPLC analysis. The IR spectra indicated that the exo-polysaccharide has an absorption peak at 890 $cm^{-1}$ for the ${\beta}-configuration$ of D-glucan. The $^{13}C$ NMR signal at ${\delta}$ 86.62 ppm arose from the substituted C-3 of glucose. The signal at ${\delta}$ 72.11 ppm was assigned to C-6 of branched ${\beta}-(1{\to}3)-D-glucosyl$ residues. Viscosity and Congo red reaction indicated that {\beta}-(1{\to}3)(1{\to}6)-glucan$ produced by A. pullulans IMS-822 has a highly ordered hydrogen-bond dependent conformation in aqueous solution, which collapses in strong alkaline solution.

• Korean Journal of Microbiology
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• v.50 no.1
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• pp.33-39
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• 2014

One hundred forty four bacterial colonies which were able to degrade crude oil were isolated from soil samples that were contaminated with oil in Daejeon area. Among them, one bacterial strain was selected for this study based on its emulsification activity, growth rate and surface tension activity, and this selected bacterial strain was identified as Pseudomonas sp. HN37 through physiological- biochemical tests and analysis of its 16S rRNA sequence. Pseudomonas sp. HN37 utilize the several aliphatic hydrocarbons, 3,5-dinitrosalicylic acid and 2,4-dichlorophooxyacetic acid as a sole carbon source. And this bacterial strain showed a high resistance to antibiotics such as ampicillin and chloramphenicol, as well as heavy metals such as Ba, Cr, Li and Mn. Also, it was found that the optimal pH and temperature for the cell growth, surface tension, and emulsification activity of Pseudomonas sp. HN37 were pH 6.0-9.0 and $30^{\circ}C$, respectively. The emulsification and surface tension activity was reached the maximum to 1% (V/V) crude oil and 1% (W/V) NaCl concentration. The surface tension of the culture broth was decreased from 62 to 27 dyne/cm after fifteen hours of inoculation in LB media.

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 1999.10a
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• pp.1-2
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• 1999

시간과 공간의 구애를 받지 않는 양질의 음성, 화상, 문자정보의 교환을 위한 노력으로 디지털 휴대폰과 휴대용 컴퓨터가 등장하면서 음성과 문자정보의 교환분야에 커다란 진보를 이룩하였다. 그러나 현재는 휴대폰이 음성정보에 문자정보교환이 추가된 상황이기 때문에, 아직도 관련 정보교환기술 및 기기개발이 진행되고 있다. 앞으로 휴대폰과 휴대용 컴퓨터의 기능을 통합하고 화상정보까지 결합된 휴대용 정보기기를 위해서는 전자회로의 집적화 및 통신속도 증대가 필수적이다. 또한 이들 휴대용 정보기기를 구동시키기 위한 전력도 증가될 것으로 예측되기 때문에, 현재 전원으로 사용되는 2차전지보다 에너지 밀도가 더욱 증패된 전지가 요구될 것으로 예상된다. 그리고 내연기관의 배기에 의해 발생되는 환정오염문제를 해결하기 위한 방법중의 일환으로 전기자동차 개발이 진행되고 있으며, 이들 전기자동차에 2차전지를 장착하기 위해서 경제성이 있고, 고속충전이 가능하고, 안전성이 높은 고에너지 밀도의 2차 전지 개발이 요구되고 있다. 현재 2차전지는 음극재료나 양극재료에 따라 낚축전지, 니켈/카드륨(Ni/Cd) 전지, 니켈/수소(Ni/MH) 전지, 라륨 2 차전지등이 있으며, 전극재료의 고유특성에 의해 전위와 애너지 밀도가 결정된다. 특히 리튬 2차전지는 리튬의 낮은 산화환원전위와 분자량으로 인해 에너지 밀도가 높기 때문에 앞에서 언급한 휴대용 전자기기의 구동전원으로 많이 사용되고 있다. 리튬 2차전지는 음극 재료가 금속리튬인 경우는 리튬금속으로, 탄소재료인 경우는 리튬이온이라 하며, 한편으로 전해질이 고체 고분자이거나 혹은 역체 유기용매와 리튬염을 고분자와 혼성시킨 겔(gel)인 경우는 고분자로, 전해짙이 리튬염이 전리되어 있는 유동성 액체일 경우는 고분자를 생략하여 구분하고 있다. 즉 리튬금속 2 차전지(LB), 리튬이온 2 차전지(LIB), 리튬금속 고분자 2차전지(LPB), 리튬 이온 고분자 2차전지(LIPB)로 크게 구분된다. 금속리듐을 음극으로 사용하고 전해질로는 리튬염이 전리되어 있는 액체유기용매 를 사용한 리튬금속 2차전지는, 금속리튬전극이 충방전 과정을 반복하면서, 전리된 리튬이 균일하게 산화환원되지 못하고 표변에서 양극방향으로 성장하는 수지상 (dendrite) 현상으로 인해 안전성 확보에 문게가 있었다. 리튬과 알루미늄 합금형태로 음극에 사용한 동전형 전지는 상용화 되었지만, 이러한 단점을 개선하기 위해 리튬이온이 금속으로 석활되는 환원반응전위보다 높은 전위에서 전극재료가 충전되면서 리튬이온이 저장되고, 방전되면서 배출되는 탄소를 음극재료로, 그리고 리튬이온이 충방 전시 가역적으로 삼입 탈리되는 층상의 리튬금속산화물을 양극으로 구성하고, 엑체 전해질과 다공성 고분자 분리막을 사용한 것이 LIB이다. LIB에서 리튬이온의 이동이 가능한 액체전해질의 가능을 고분자 전해질이 대신함으로서 보다 높은 안정성을 확보 한 전지가 LIPB 이다. 또한 고분자 전해질을 사용한 경우 금속리튬상에서의 수지상 성장이 저하되는 현상이 관찰됨으로서, 이론용량이 3,860mAh/g 에 달하는 리튬금속 혹은 합금을 고분자 전지에서 음극으로 사용하고자 하는 2 차전지가 LPB 이다. 리튬 2차전지는 비록 1989년 액체전해질을 사용한 금속리튬 2차전지의 실패전력을 안고있지만 궁극적으로는 이론적으로 최대의 에너지밀도를 가지고 있는 LPB를 지 향할 것으로 예상되지만 가까운 장래에 실현되기는 어려울 것이다. 따라서 향후의 라튬 2차전지의 전개방향은 현재의 LIB를 고분자 전해질을 채용하는 LIPB로 진행시커면서 저가의 전극재료개발을 지속적으로 추진할 것으로 예상된다. 현재 리튬 2차전지는 소형전지에 국한되고 있지만 전기자동차나 전력저장용으로 이를 대형화시커기 위해서는 열적특성이 우수하고 저가인 전극재료개발이 선행되야하기 때문에, 저가의 탄소재료와 코발트산화물을 대신할 수 있는 철, 망칸 또는 니켈산 화물의 개발이 필요하다.

• The Korean Journal of Pesticide Science
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• v.13 no.2
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• pp.63-69
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• 2009

New morpholinylcarbonylmethyl-2-phenylimino-1,3-thiazolines 2(X=O) and piperidinylcarbonylmethyl-2-phenylimino-1,3-thiazolines 3(X=C) to which morpholinyl or piperidinyl functional group were introduced at C-4 side chain of the 2-phenylimino-1,3-thiazoline scaffold were synthesized to investigate the effect of NH hydrogen of 2-phenylimino-1,3-thiazoline-4-acetanilide derivatives on the antifungal property against rice blast. Synthesized 30 compounds were screened against 6 kinds of typical plant fungi. Treatment of ketene dimer with chlorine followed by the reaction of morphorine or piperidine without isolation of the intermediate acetoacetylchloride gave $\gamma$-chloro-$\beta$-keto derivatives. These were reacted with thioureas to give morpholinylcarbonylmethyl-2-phenylimino-1,3-thiazolines and piperidinylcarbonylmethyl-2-phenylimino-1,3-thiazolines respectively in good yield (27-98%). The compound 3j, in which two fluorine atoms are substituted at ortho and para position of phenyl group of 2-phenylimino moiety and piperidinyl group is substituted at C-4, showed the highest antifungal activity (100 ppm, 90%). This result suggested that the substituent at C-4 of the 2-phenylimino-1,3-thiazolines may play a supplementary role to show the antifungal activity against rice blast.

• Journal of Life Science
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• v.24 no.4
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• pp.437-446
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• 2014

Problems appear when triptans are taken orally. For example, the bioavailability of triptan is reduced by the digestive system, and the drug level in the blood reduces rapidly over time; there is also a possibility of gastrointestinal disorder. To improve side effects, a transdermal patch has been prepared in hydrogel form. The polymer matrix that makes up the hydrogel uses PVA; PEG is used as an additive to induce inter/intra hydrogen bonding of the PVA and almotriptan drug is added. In addition, to accelerate micro-phase separation between PVA chains, liquid nitrogen is used. In FT-IR analysis, the absorption bands of PVA, PEG, and almotriptan were found. The degree of crystallinity, the water uptake ability and tensile strength were increased with increasing PEG content. In drug release tests, the amount of drug released increased depending on the PEG content. In this study, hydrogels with 10 wt% PEG showed better performance in drug release. Approximately 60% of the total drug amount was released in 2 hr, and the drug continued to release for 1 day. Thus, the prepared hydrogel patch is suitable as a transdermal formulation for the second dose administration of triptans to patients who require recurrent migraine treatment within 24 hr after the first administration.

• Korean Journal of Food Science and Technology
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• v.17 no.3
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• pp.213-218
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• 1985

As a way of improving the texture and flavor of soybean cheese, whey-say cheeses were made by coprecipitation of various mixtures of whey, whey powder, soy milk and soy protein powder, and mixed culture of str. lactis, str. cremoris and rennet were added, then the cheeses were cured at $15^{\circ}C$ for up to 10 weeks. Physicochemical characteristics of the cheese were investigated by analyzing pH, titratable acidity(TA), water soluble nitrogen, 10% TCA soluble nitrogen, amino acid composition, beany flavor, color and hardness. The pH of whey-soy cheeses during ripening changed from 5.3 to 4.2 after 5 or 6 weeks and maintained that value while that of soybean cheese maintained a higher pH value. TA of whey-soy milk cheeses was gradually increased to the value of 0.4-0.45 after 8 weeks, but that of soybean cheese reached only 0.2 after the same period. Water soluble and 10% TCA soluble-nitrogen increased steadily during ripening. Hardness of the whey-soy milk cheeses reached maximum after three weeks of ripening and greatest at those made from 3 : 1 mixture of whey and soy milk and that from soymilk. Color of the whey-soy milk chesses was lighter than that of soybean cheese. The bean flavor of soybean cheese was strong and persistent for the whole ripening period. Acid flavor was dominant in the whey-so milk cheese and masked the beany flavor partially.

• Korean Journal of Food Science and Technology
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• v.2 no.2
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• pp.61-67
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• 1970

The growth characteristics of Candida tropicalis KIST 359, isolated from soil samples collected at an oil depot in Korea, have been studied by cultivating batches under varying conditions. The conclusions of the study were: 1. The yeast easily assimilates hydrocarbons in a range of $C_{14}-C_{17}$, and the optimum cultivation temperature and pH are $30^{\circ}C$ and 5.5, respectively. 2. Using this strain of micro-organism, gas oil gives a higher cell yield than kerosine and with gas oil except urea all other nitrogen sources $(NH_4NO_3,\;NH_4Cl,\;(NH_4)_2SO_4\;and\;(NH_4)_2HPO_4)$ similarly support a satisfactory growth of the yeast. 3. The highest yield is obtained with a gas oil level of 10%(v/v), and concentrations of nitrogen source and $MgSO_4{\cdot}7H_2O$ of 0.5 and 0.05%(w/v), respectively. 4. The protein content of dried yeast cells is 59.8%. Its amino acid composition can be compared well with that of FAO provisional patterns, but with a low methionine and a high lysine content.

• Applied Biological Chemistry
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• v.46 no.3
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• pp.251-256
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• 2003

The polyphenol fractions of Korean ginseng were purified using Sephadex LH-20, MCI gel, Bondapak $C_{18}$ TLC, and HPLC from the 60% acetone soluble fraction. Fraction I showed 48.16%, 79.71% and 43.55% inhibition at 150 ppm against lipid oxidation in the presence of copper ion, superoxide and hydrogen peroxidation. Electron donating abilities of fraction II showed 35.17% inhibition at 200 ppm. Fraction III showed 48.49% and 25% inhibition at 150 ppm against lipid oxidation in the presence of ferrous ion and hydroxy radical ion. The phospholipase $A_2$ inhibitory effect of fraction III was 48.9% at the concentration of $60\;{\mu}g/ml$. The cytotoxic effects of fraction II was the highest (73.29% at 0.25 mg/ml) among the tested polyphenol fractions.

• Korean Journal of Pharmacognosy
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• v.35 no.3 s.138
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• pp.207-214
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• 2004

This study was investigated antioxidatve activity for the purpose of developing antioxidant from Morus bombycis Koidzumi. Antioxidant activities of four different organs of Morus bombycis Koidzumi such as fruit, leaf, stem, and root were examined by radical scavenging effect with 1,1-diphenyl-2-picrylhydrazyl (DPPH). 80% methanol extract from the stem showed strongly antioxidative activity and 80% Ethanol extracts from the root, stem, and fruit had high antioxidative activity among 24 samples tested. The 80% ethanol extract has strong absorbency at UVA region (350 nm). The ethyl acetate (EtOAc) fraction exhibited antioxidative activity with $IC_{50}$ of $15.0\;{\mu}g/ml$ similar to those of synthetic antioxidant, BHT The EtOAc fraction has a good absorbency property as synthetic filter. In the absorbance of various extracts, the 80% ethanol and ethyl acetate extracts from the root of Morus bombycis Koidzumi showed higher absorbancy at 285 nm. The ethyl acetate fraction from the root of Morus bombycis Koidzumi contained total phenolic compounds of 654.8 mg/100 g. These results indicate that phenolic compounds are the major was biological components in the root of morus bombycis Koidzumi extracts. Considering these biological activities, the extracts of Morus bombycis Koidzumi showed a possibility to be used as a new material for natural anti-oxidants and substitutes for synthetic UV sunscreen agents.

• Journal of the Korean Wood Science and Technology
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• v.35 no.6
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• pp.65-72
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• 2007

The VOC (volatile organic compound) analyzer is devised to measure the four main aromatic hydrocarbon gases: toluene, ethylbenzene, xylene and styfene. It is not affected by ambient temperature and humidity. In addition, standby and measuring time of VOC Analyzer is a short as below 30 min and 8 min, respectively. Since the semiconductor gas sensor is supersensitive to gas components, it is not necessary to use a conventional gas concentrator or other complicated equipment. In this study, VOC emission behavior from 4 types paints (lacquer, urethane vanish, water-base paint, enamel paint) for wood-based panel was investigated using VOC Analyzer. After a specimen was spreaded on aluminum foil ($6.32{\times}6.32cm$) in $3{\ell}$ polyester bag, after 24 hours we could measure maximum VOC emission level that is a stabilized VOC value. Xylene of VOCs was high emitted from lacquer, urethane vanish and water-based paint, and TVOC (Toluene + Ethylbenzene + Xylene + Styrene) of lacquer was the highest emission concentration than another.