• Journal of Marine Bioscience and Biotechnology
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• v.1 no.4
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• pp.260-267
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• 2006

The Liquid Culture Assay using a recombinant Agrobacterium tumefaciens strain has been developed as a means for quorum sensing autoinducer screening. However, the low aqueous solubility of marine natural product extracts used as potential autoinducers has been a hindrance in the screening process. Although the addition of organic solvents and/or surfactants could increase aqueous solubility, errors in data interpretation including false positive results could be a serious problem. Therefore, determining the best possible solvent and surfactant at the optimum concentration is crucial. Evaluating methanol, ethanol, 1-propanol, DMSO and DMF at concentration ranges of 0~10% revealed < 2% methanol to be most favorable when tested for ${\beta}$-gal activity and growth inhibition of the recombinant A. tumefaciens strain. On the other hand, among surfactants tested, Triton X-100 was similarly effective in increasing the delivery of autoinducers for activity at less than 0.05% concentration.

• Economic and Environmental Geology
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• v.53 no.6
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• pp.677-685
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• 2020

The host rock of the Usuki Stone Buddha Statues is dark gray welded tuff involved the Aso-4 pyroclastic flow sediments. This Buddha Statues are processing chlorosis from rainfall flowing above and underground water which were urgently needed for conservation measurement. White precipitates, the main source of salt weathering, on the surface of the Buddha Statues are mainly consisted of thenardite, gypsum and dolomite. Extraction experiment result shows that thenardite was dissolved at the beginning of stirring and then redissolved after 4 hours, and gypsum was detected until stirring for 2 hours, and then dissolved after stirring for 4 hours. As a result of monitoring the microclimate environment for 11 months to determine the recrystallization environment of white precipitates, the phase transition between thenadite and mirabilite appears widely in spring, and is maintained in an aqueous solution due to high temperatures in summer and fall. In winter, mirabilite is shown the widest by decreasing temperature. Therefore we requires details monitoring for blocking water transfer port and solved humidity environment in shelter.

• Proceedings of the Korean Radioactive Waste Society Conference
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• 2004.06a
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• pp.229-229
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• 2004

원자력발전소에서 원자로 냉각재 중의 용존산소 제어는 원자로 냉각재 계통에서의 전면 부식과 다양한 형태의 응력부식균열(SCC)를 완화시키는데 기여한다. 원자로 냉각재 계통내에 용존 되어있는 산소는 발전소 기동 시에는 하이드라진($N_2H_4$)을 넣거나 인위적 배기를 통해 제거하고, 정상운전 중에는 체적제어탱크(VCT)에 수소를 가압하여 제거시킨다. 계통내로 유입되는 용존산소를 최대한 억제하기 위하여 대부분의 원자력발전소는 원자로 보충수 탱크 상층부에 질소를 주입하여 탱크로 유입되는 공기를 차단하고 있으나, 이 과정에서 일부 수중에 용해되어 들어가는 질소는 계통 내에서 NH$_3$를 형성하여 화학체적제어계통(CVCS)의 이온교환 수지탑에 치환됨으로서 기포화 되어있는 Li을 계통으로 빠져나오게 하여 계통 pH에 영향을 미친다.(중략)

• Journal of the Korean Society of Clothing and Textiles
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• v.23 no.1
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• pp.111-119
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• 1999

가수분해된 네 개의 반응성 염료를 이용하여 견, 양모 나일론 섬유를 염색할 때 영향을 미치는 여러 인자들에 대하여 연구하였다 염의 투입을 가수분해 전과 후로 달리하였을 때 염색된 직물의 K/S 값에 미치는 영향은 염료와 직물의 종류에 따라 각기 달랐으며 염의 영향은 염료의 분자 크기가 클 때 더 크게 나타났다. 이는 염 노동의 증가시 염욕 안에서의염료 용해도가 염료 분자가 클 때 더많은 영향을 받기 때문인 것으로 생각된다. 욕비 증가시에는 염색된 직물의 K/S값은 초기에 감소를 보이다가 높은 욕비에서 K/S값이 증가되었는데 이는 염의 농도의 감소로 인한 영향으로 사료된다. 가수분해된 반응성 염료로 염색된 직물의 수세 견뢰도는 염료의 분자 크기에 의해 영향을 받았으며 직물의 마찰 땀 견괴도는 Gray scale에서 3보다 높았다 본 연구의 결과는 면섬유 염색에 사용한 가수분해된 반응성 염료를 이용하여 견, 양모, 또는 나일론섬유의 염색에 재 사용할 수 있는 가능성을 제시하여 준다.

• The Journal of Dong Guk Oriental Medicine
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• v.7 no.2
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• pp.121-140
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• 1999

The various oriental herbal medicines, which have usually been used for treatment of reducing fever, purging intense heat and detoxication, were screened to determine the antibacterial activity and the minimal inhibitory concentration against pulmonary disease-causing Klebsiella pneumoniae, Streptococcus pyogenes, and Streptococcus pneumoniae. The results obtained were as follows: 1. Among the 23 oriental medicines tested, the water-soluble extracts of Coptis japonica, Scutellaria baicalensis and Picrorrhiza kurrooa showed the antibacterial activity against K.pneumoniae and that of C. japonica against S. pyogenes. The antibacterial activities of C. japonica, Prunusmume, Schizandra chinesis, Scutellaria baicalensis were also found against S.pneumoniae. When C.japonica was used, the high antibacterial activity was shown against Bacillus subtilis and other extracts showed a little activity against B. subtilis and E. coli as a control. 2. The ethanol-soluble extracts of Patrinia scabriosaefolia, P. mume, S. baicalensis, S. chinesis showed the antibacterial activity against K. pneumoniae and those of S. baicalensis, C. japonica, S. chinesis, P. mume agaist S. pyogenes and S. pnuemoniae. However, those extract showed a little antibacterial activity against B. subtilis and E. coli except for that the extract of C. japonica showed comparatively high growth inhibition of B. subtilis. 3. Among the medicinal herbs tested, the water and ethanol extrats of C. japonica showed very extcellent antibacterial activity against the pathogenic bacteria and controls. 4. When the water-soluble extracts of C. japonica and S. baicalensis, minimal inhibitory concentrations (MICs) against K. pneumoniae were $10mg/m{\ell}$ and $22 mg/m{\ell}$, respectively. The MICs of the ethanol-soluble extracts of P. mume and P. scabriosaefolia were $5mg/m{\ell}$ and $20mg/m{\ell}$, respectively. 5. For the MICs against S.pyogenes, C. japonica showed $15mg/m{\ell}$ with the water-soluble extract and P. mume and C. japonica with the ethanol-souble extract did $5mg/m{\ell}$ and $10mg/m{\ell}$, respectively. 6. For the MICs against S. pneumoniae, C. japonica and P. mume with the water- and ethanol-souble extract showed $5mg/m{\ell}$ and $10mg/m{\ell}$, respectively. As a result, the highest antibacterial activity was found in the water- and ethanol-soluble extracts of C. japonica against pulmonary disease-causing bacteria, K. pneumoniae, S. pyogenes. and S. pnuemoniae. Also, the water- and ethanol-soluble extracts of S.chinesis. P.mume, S.baicalensis, and P.kurrooa showed hight antibacterial activities.

• Analytical Science and Technology
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• v.22 no.6
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• pp.514-518
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• 2009

Coenzyme $Q_{10}$($CoQ_{10}$), a vitamin E-like substance, represents a components of the complex antioxidant system of the human organism. $CoQ_{10}$ levels in human plasma were determined by high performance liquid chromatography (HPLC) with UV detection. It was dissociated from lipoproteins by methanol and extracted into n-hexane with liquid-liquid extraction procedure, after centrifugation, the supernatant was dried under nitrogen gas stream. The residue was dissolved in the absolute ethanol. Determination of $CoQ_{10}$ was performed on a $C_{18}$ reversed-phase analytical column with ultraviolet detection at 275 nm and the mobile phase containing 15% (v/v) ethanol in methanol at a flow rate of 1.7 mL/min. The low limit of quantitation was 0.02 mg/L (S/N=10), the linearity between the concentration and peak height is from 0.1 to 2.0 mg/L. Twenty-four randomly selected plasma samples from apparently healthy, 27 to 44 year old individuals (males and females) were analyzed for total $CoQ_{10}$. The average level in these subjects was $0.62{\pm}0.13mg/L$ with the range of 0.41-0.98 mg/L. This method has a specific and a sufficient limit of quantitation (LOQ) for analysis of $CoQ_{10}$ in human plasma in both a clinical study and research at laboratories.

• Tuberculosis and Respiratory Diseases
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• v.40 no.2
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• pp.123-134
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• 1993

Background: Tissue-type plasminogen activator is a physiologic activator, which has high affinity for fibrin and is activated by fibrin. Because of these properties, t-PA has the potential to induce effective thrombolysis without producing a systemic lytic state. In practice, however, therapeutically efficacious doses of t-PA has been associated with the development of a systemic lytic state. As experience with t-PA has accumulated, it has suggested that the fibrin selectivity is influenced by the dose and duration of t-PA infusion, and many studies have performed in an attempt to optimize the duration of t-PA regimen. Methods: This study was designed to assess the thrombolytic efficacy of t-PA and the differences of two dosing regimens of t-PA (infusion of 1 mg/kg t-PA over 15 or 180 minutes) in a canine model of pulmonary embolism, induced by injection of radioactive autologous blood clots. By continuously counting over both lung fields with a external gamma counter, we correlated rate and extent of pulmonary thrombolysis with corresponding pulmonary hemodynamics in addition to the gas analyses of arterial and mixed venous blood. Results: 1) While total clot lysis was similar ($36.2{\pm}3.3%$ and $39.6{\pm}2.3%$ respectively, p>0.05) when t-PA was infused over 15 or 180 minutes, the rate of lysis during infusion was markedly increased with the shorter infusion ($81.4{\pm}16.8%/hr$ vs $37.3{\pm}2.4%/hr$, p<0.05). 2) The duration of thrombolysis was $63.3{\pm}22.2$ minutes although t-PA was administered over 15 minutes, and it was only $148.5{\pm}14.0$ minutes in case of the infusion over 180 minutes (p<0.05). 3) The increased rate of thrombolysis with the shorter infusion was accompanied by a faster amelioration of cardiopulmonary impairment from pulmonary embolism (p<0.05). Conclusion: It is concluded that the shorter (15 minutes) infusion of t-PA is superior to the longer (180 minutes) infusion when the dose is equal, in consideration of the faster improvement in cardiopulmonary impairment from pulmonary embolism.

• Journal of Animal Science and Technology
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• v.51 no.4
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• pp.337-342
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• 2009

The feasibility of reutilization of magnesium ammonium phosphate (MAP) or struvite slurry recovered from the process through microwave irradiation was studied in this experiment. For this purpose, 4 different operations were performed with or without Mg source addition and different levels of MAP recycled in a batch reactor. Dissolution rate of MAP, ${NH_4}^+$ elimination pattern and physicochemical changes of MAP during microwave irradiation were also studied. The result showed that only 33% orthophosphate ($PO_4-P$) and 27% $NH_4-N$ removal occurred without adding any external Mg source (run A), whereas 87% $PO_4-P$ and 40% $NH_4-N$ removed when 1.0 M ratio of $MgCl_2$ (run B) was added based on $PO_4-P$ in influent. Although the addition of 1.0 molar ratio of microwave irradiated MAP (Run C) removed lower $PO_4-P$ and $NH_4-N$ than 1.0 M $MgCl_2$ (run B), $PO_4-P$ removal was double when compared with no Mg addition (run A). Addition of half MAP and half $MgCl_2$ (run D) showed the similar removal efficiency (88% $PO_4-P$ and 35% $NH_4-N$) with sole $MgCl_2$ addition (run B). Based on these results, the reutilization of MAP irradiated by microwave would be a feasible way to enhance the removal efficiencies of N and P, as well as curtail the Mg chemical usage. Track study showed that $NH_4-N$ gradually increased at initial stage of microwave irradiation of MAP, and then started eliminating from liquor as temperature increased over $45^{\circ}C$. Dissolution rate of ${PO_4}^{-3}$ during microwave irradiation was proportional to the initial MAP concentration, having $0.0091x^{0.6373}$ mg/sec. It was found from the scanning electron microscope (SEM) study that physical structure of MAP crystal started breaking down into small cube granules within very short time by electromagnetic vibration force during microwave irradiation and then gradually melted down into solution.

• Resources Recycling
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• v.9 no.1
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• pp.36-43
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• 2000

This study was carried out for treatment and reuse of inorganic sludge from Fenton process at B dyeing wastewater treatment plant. The parameters for pilot-scale treatment system were derived from the results of this study. It was found that $COD_{cl}$ of the treated effluent became lower than 100 mg/l approximately on the optimal reaction condition. 2nd sludge which was generated after redissolving sludge was analyzed, and it showed that reduction ratio of ash in 2nd sludge and total dry sludge weight in comparison with current sludge were 85% and 65%. Also Fe salt in sludge was redissolved about 90~95% of initial Fe by weight. It was estimated almost ￦350,000,000 for sludge reuse process. It was estimated saving of about ￦1,300,000 per day (￦420,000,000 per year) in operating cost based on 30,000 $m^3$/d treatment, which these were about ￦430,000 per day in chemical, ￦1,100,000 per day in sludge transportation and ￦200,000 per day in equipment maintenance. Payback period with interest charge for investment cost was estimated about 10.5 months. Also, net present value (NPV) was ￦792,000,000 and internal rat of return (IRR) was about 110%.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.14 no.11
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• pp.6029-6038
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• 2013

In this study we attempt to modify the backbone structure and improve processibility of PBO having high melting and glass transition temperature. A series of aromatic poly(o-hydroxyamide)s(PHAs) were synthesized by direct polycondensaton of diacides containing diimide unit with two types of bis(o-aminophenol)s including 3,3'-dihydroxybenzidine and 2,2-bis(3-amino-4-hydroxyphenyl)hexafluoropropane. PHAs were studied by FT-IR, $^1H$-NMR, DSC and TGA. PHAs exhibited inherent viscosities in the range of 0.34~0.65 dL/g at $35^{\circ}C$ in DMAc solution. The PHA 1 and 6F-PHA 6, introducing o-phenylene unit in the main chain showed excellent solubilities in aprotic solvents such as NMP etc. However, the PHA 3, having p-phenylene unit was not even dissolved perfectly with LiCl salt. 6F-PHAs were readily soluble at room temperature in aprotic solvents except 6F-PHA 3. But they showed better solubility than that of PHAs. The polybenzoxazoles(PBOs) were quite insoluble in other solvents except partially soluble in sulfuric acid. PBOs exhibited relatively high glass transition temperatures(Tg) in the range of 306~$311^{\circ}C$ by DSC. The maximum weight loss temperature and char yields of PHA3 and 6F-PHA3 showed the highest values of $658^{\circ}C$ and $653^{\circ}C$, 62.6 % and 62.1 %, respectively.