• Bulletin of the Korean Chemical Society
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• 제21권11호
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• pp.1125-1132
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• 2000

The pH effect of the precursor solution on the preparation of $LiCoO_2$ by a solution phase reaction containing malonic acid was carried out. Layered $LiCoO_2$ powders were obtained with the precursors prepared at the different pHs (4, 7, and 9) and heat-treated at $700^{\circ}C(LiCoO_2-700)$ or $850^{\circ}C(LiCoO_2-850)$ in air. pHs of the media for precursor synthesis affects the charge/discharge and electrochemical properties of the $LiCoO_2electrodes.$ Upon irrespective of pH of the precursor media, X-ray diffraction spectra recorded for $LiCoO_2-850$ powder showed higher peak intensity ratio of I(003)/I(104) than that of $LiCoO_2-700$, since the better crystallization of the former crystallized better. However, $LiCoO_2$ synthesized at pH 4 displayed an abnormal higher intensity ratio of I(003)/I(104) than those synthesized at pH 7 and 9. The surface morphology of the $LiCoO_2-850$ powders was rougher and more irregular than that of $LiCoO_2-700$ made from the precursor synthesized at pH 7 and 9. The $LiCoO_2electrodes$ prepared with the precursors synthesized at pH 7 and 9 showed a better electrochemical and charge/discharge characteristics. From the AC impedance spectroscopic experiments for the electrode made from the precursor prepared in pH 7, the chemical diffusivity of Li ions (DLi+) in $Li0.58CoO_2determined$ was 2.7 ${\times}$10-8 $cm^2s-1$. A cell composed of the $LiCoO_2-700$ cathode prepared in pH 7 with Lithium metal anode reveals an initial discharge specific capacity of 119.8 mAhg-1 at a current density of 10.0 mAg-1 between 3.5 V and 4.3 V. The full-cell composed with $LiCoO_2-700$ cathode prepared in pH 7 and the Mesocarbon Pitch-based Carbon Fiber (MPCF) anode separated by a Cellgard 2400 membrane showed a good cycleability. In addition, it was operated over 100 charge/discharge cycles and displayed an average reversible capacity of nearly 130 mAhg-1.

• Journal of Applied Biological Chemistry
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• 제58권3호
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• pp.247-251
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• 2015

In this study, a keratin-degrading bacterium was isolated from soil contaminated with feather waste. The isolated strain was identified as Chryseobacterium sp. P1-3 on the basis of the 16S rRNA gene sequence alignment. Chryseobacterium sp. P1-3 is currently used in various biotechnological applications (e.g., in the hydrolysis of poultry feathers). It hydrolyzed the feather meal within 2 days and possesses a high level of keratinase activity (98 U/mL). The keratinase, partially purified from this strain, prefers casein as a substrate and shows optimal activity at a temperature of $30^{\circ}C$ and at a pH of 8.0.

• 한국약용작물학회지
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• 제19권4호
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• pp.271-275
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• 2011

In this study, ginseng flower water extracts were analyzed to set up the ginsenoside content and quality optimization condition. The highest total ginsenoside content among the ginseng flower water extracts was 67.44mg/g which was extracted at $85^{\circ}C$ for 3 hours. In addition, the ginsenoside content decreased according to the increased extraction temperature and time. The highest total content of $Rb_2$ and Re was 37.42mg/g at $75^{\circ}C$ for 6 hours. Total content of $Rb_2$ and Re decreased according to the increased extraction temperature and time. The highest prosapogenin ($Rg_2$ + $Rg_3$ + $Rh_1$) content among the total of ginseng flower water extracts was 18.58mg/g which was extracted at $95^{\circ}C$ for 12 hours. The sweetness, absorbance were increased according to the increased extraction temperature and time. But pH was decreased according to the increased extraction time.

• BMB Reports
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• 제38권3호
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• pp.343-349
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• 2005

Gamma-glutamyltransferase (GGT, EC 2.3.2.2) which hydrolyzes glutathione (GSH), is required for the maintenance of normal intracellular GSH concentration. GGT is a membrane enzyme present in leukocytes and platelets. Its activity has also been observed in human neutrophils. In this study, GGT was purified from Triton X-100 solubilized neutrophils and its kinetic parameters were determined. For kinetic analyses of transpeptidation reaction, $\gamma$-glutamyl p-nitroanilide was used as the substrate and glycylglycine as the acceptor. Apparent $K_m$ values were determined as 1.8 mM for $\gamma$-glutamyl p-nitroanilide and 16.9 mM for glycylglycine. The optimum pH of GGT activity was 8.2 and the optimum temperature was $37^{\circ}C$. It had thermal stability with 58% relative activity at $56^{\circ}C$ for 30 min incubation. L-serine, in the presence of borate, was detected as the competetive inhibitor. Bromcresol green inhibited neutrophil GGT activity as a noncompetetive inhibitor. The neutrophils seem to contain only the isoenzyme that is present in platelets. We characterized the kinetic properties and compared the type of the isoenzyme of neutrophil GGT with platelet GGT via polyacrylamide gel electrophoresis (PAGE) under a standart set of conditions.

• 한국실내디자인학회논문집
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• 제8호
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• pp.58-64
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• 1996

People live in an environment which affects the human b by way of ‘Affordance’ .. And the interaction between h human and the surrounding environment arises ‘the sense of place' through adoptation. Considering the human emo¬t tional and psychological needs, besides the functionalones, for the design of environment gives ‘the place’ the h humanized atmosphere. Then the viewing-window, re¬f fleeting the dweller’s sensibility and aesthetic aspect, be¬c comes an important design element for the human interi¬o or atmosphere. G Generally, the view has the character of the Panorama a and sometimes of the Picture. And the viewing - window t transfigures the visual effects by ways of ‘Framing’, at t taching the ’Screen’ and ‘Successive development' of the views through openings on the wall. Hence this study w was developed from the aesthethic view-points of archi t tecture, cinema, picture and photography etc., and the c conclusions are as follows. T The ‘Frame’ limits the boundary of the view into a p particular area, while the ‘Screen’ changes the clear view t to an obscure one. And the wall-openings located with i intervals show the fragments of the outer view in a suc¬c cessive way. And these techniques applied to the viewing window make the viewer have the associated meanings d derived from the ‘Guided Projection'. So, the associative p psychology of the viewer complements the partiality, ob¬s scurity and brokenness of the view into a complete one, a and finally the view comes to be an aesthetic one to the v vIewer.

• Journal of the Korean Wood Science and Technology
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• 제37권1호
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• pp.94-104
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• 2009

본 연구는 폐바이오매스로서 활엽수(hardwood, HW)톱밥, 침엽수(softwood, SW)톱밥, 산야초류(grass) 등 3종의 발효재료를 이용, 3종의 나선형 열교환기와 1종의 평판형 열교환기를 제작하여 발효과정에서 생산되는 발효열을 가장 효율적으로 회수할 수 있는 발효열 교환장치 개발을 위하여 실시하였다. 본 연구에서는 다양한 바이오매스재료의 적절한 원료 배합을 통한 발열 및 열교환 특성을 조사하고 실제 농가에 설치 및 해체가 용이한 열교환기를 개발하였으며, 그 결과를 요약하면 다음과 같다. 나선형 열교환기를 사용한 발효열 실험에서 활엽수톱밥 및 침엽수 : 활엽수톱밥(50 : 50) 처리보다는 활엽수톱밥 : 산야초(90 : 10)의 발효가 약 3개월간의 긴 발열기간을 나타냈으며, 발효상을 통과한 물의 온도를 100일간 측정한 결과, 중앙부가 $64.5{\sim}76.5^{\circ}C$로 매우 높았고, 물탱크 온도는 $33{\sim}48^{\circ}C$ 범위였으며, 출구의 수온은 $33{\sim}44^{\circ}C$로서 4~5인 기준의 가정용 온수공급이 가능함이 확인되었다. 수행한 4종의 열교환기 실험 결과, 나선형 열교환기 HX-H1은 수온이 $35{\sim}36^{\circ}C$범위로서 더 이상의 온도상승이 없었고, HX-H2는 수온이 $40{\sim}45^{\circ}C$로서 실험기간 중 일정한 온도분포를 보였다. 한편 HX-H3는 최고온도 $68{\sim}70^{\circ}C$, 최저온도 $30^{\circ}C$, 평균온도 $50^{\circ}C$였고, 출구의 온수온도는 $33{\sim}44^{\circ}C$ 범위로서 45일간 공급 가능하였다. 평판형 열교환기 HX-P는 수온이 $42{\sim}58^{\circ}C$로서 3개월 이상 온수공급이 가능하였으므로 4~5인 기준의 가정용 난방 및 온수공급에 문제가 없는 것으로 확인되었다. 그러므로 평판형 열교환기 HX-P는 나선형 열교환기 HX-H에 비해 발효상 내부에 열교환용 파이프가 빈틈없이 배치되어 발효상 전면적을 통해 발효열을 최대로 회수할 수 있었으며, $42{\sim}58^{\circ}C$의 발효열을 최대 3개월정도 이용 가능하였고, 장시간 운용에도 온도가 급강하 하는 등의 문제가 발생되지 않았다. 따라서 발효열교환기는 나선형 시스템보다는 발효열의 회수 효율이 매우 높으면서도, 열교환장치의 제작, 설치, 해체가 용이한 평판형 시스템이 유리한 것으로 나타났다.

• 한국축산식품학회지
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• 제27권3호
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• pp.377-381
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• 2007

본 연구는 육포를 실온조건과 가속조건 하에서 저장하면서 육포의 양념, 포장조건과 환경조건에 따른 육포의 미생물균수의 변화와 이화학적 품질의 변화를 관찰하기 위하여 실시하였다. 육포 저장중의 일반세균수는 실온조건 저장과 가속조건 저장 모두에서 큰 변화가 없었고, 대장균군과 B. cereus는 전 저장기간 동안 검출되지 않았다. 저장기간 동안의 이화학적 특성은 점차 감소하는 경향을 나타내었다. 모든 육포에서의 관능검사는 저장기간이 길어짐에 따라 점차적으로 감소하는 경향을 보였으며, 가속조건에서 전체적인 기호도는 육포의 상품성이 없어지는 시점을 5라고 했을 경우 28일째에 5.54의 값을 나타내었다. 실온조건 저장의 경우 전체적인 기호도는 7.13으로 우수한 관능검사 성적을 나타내었다. 따라서 본 실험의 결과를 통해 새롭게 개발한 한국형 고추장 양념 돈육포는 미생물학적인 안전성이 우수하고, 이화학적 품질과 관능적 품질이 비교적 우수한 육포라고 판단하였다.

• 한국수산과학회지
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• 제45권6호
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• pp.635-639
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• 2012

Thawing is very important in tuna canning because it affects the yield and quality of the canned tuna, and productivity. The effects of vacuum thawing on the quality, yield, and thawing times of frozen skipjack were compared with conventional water immersion thawing. The time required to thaw frozen skipjack tuna (weight 2.5-3.0 kg) from $-10^{\circ}C$ to $-2^{\circ}C$ was 75, 60, and 37 min at a pressure of 17, 23, and 31 mmHg, respectively, corresponding to temperatures of 20, 25, and $30^{\circ}C$. The thawing time decreased with increasing pressure. Vacuum thawing shorten the thawing time by 58-80% compared with water immersion thawing at $20^{\circ}C$, and there was less difference between the core and skin temperatures than with water immersion thawing. No significant change in pH or histamine was observed according to thawing method, while the volatile basic nitrogen (VBN), trimethylamine (TMA), and K value were lower with vacuum thawing than water immersion thawing. Based on these results, we believe that vacuum thawing minimizes the biochemical and microbial changes that occur while thawing frozen skipjack tuna.

• Transactions on Electrical and Electronic Materials
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• 제3권3호
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• pp.29-33
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• 2002

A procedure was developed for preparing bulk carbon nitride crystals from a polymeric $\alpha$ -C$_3$N$\_$4.2/ at high pressure and temperature in the presence of seeds of crystalline carbon nitride films prepared by a high voltage discharge plasma combined with pulsed laser ablation of graphite target. The samples were evaluated by x-ray photoelectron spectroscopy (XPS), infrared (IR) spectroscopy, Auger electron spectroscopy (AES), secondary-ion mass spectrometry (SIMS), scanning electron microscopy (SEM) and x-ray diffraction (XRD). Notably, XPS studies of the film composition before and after thermobaric treatments demonstrate that the nitrogen composition in $\alpha$ -C$_3$N$\_$4.2/ material initially containing more than 58% nitrogen decreases during the annealing process and reaches a common, stable composition of ~45%. The thermobaric experiments were performed at 10-77 kbar and 350-1200 $\^{C}$.

• Journal of Nutrition and Health
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• 제12권1호
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• pp.51-58
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• 1979

It is a general trend everywhere that the uses of vegetable oils are increasing due to the fact that they are effective in curing and preventing symptoms of high blood pressure and various heart failure conditions. At the same time the concept that oxidative rancidity is caused by the oxidation of unsaturated fatty acid moieties whose subsequent decomposition gives rise to various undesirable, sometimes toxic compounds is now well accepted. Linolenic acid (C, 18:3) is one of highly unsaturated and readily oxidizable fatty acid. The content of this essential polyunsaturated fatty acid in perilla seed oil (PSO) was found to be as high as 48% while only 1.5% in sesame seed oil (SSO). In this experiment the oxidative stability of PSO was compared with that of SSO. The experimental test group were as follows: A) Stored at different temperatures, namely $4^{\circ}C,\;30^{\circ}C,$ and $60^{\circ}C,$ B) Stored at room temperature $(20{\pm}5^{\circ}C)$ ; a. protected from sunlight and air, b. exposed to air without sunlight c. exposed to sunlight but protected front air, d. completely exposed to both air and sunlight. The following results were obtained; 1) It was found to be most stable against oxidation to store both PSO and SSO under the low temperature $(4^{\circ}C)$ condition. According to P.V. measurements it was found to be safe to keep both oils up to $30^{\circ}C$ for at least 8 weeks. When exposed to air, sunlight and high temperature $(60^{\circ}C)$, P.V. of PSO reached there peak values, which were much higher than those of SSO. This explains much of its instability as compared to SSO against oxidation. 2) The effect of high temperature $(60^{\circ}C)$ on A.V. was found to be more striking than those of all the other storage conditions. The condition of refrigeration was most effective in keeping A.V. low for both oils as was the case in P.V. 3) For both oils, I.V. decreased throughout the experimental period (8 weeks). The range of decrement was larger for PSO than SSO. 4) There was no significant change in the compositions of fatty acids of SSO caused by various experimental storage conditions. But for PSO the compositions of stearic, oleic and linoleic acid were decreased, whereas linolenic acid was increased proportionally.