• 한국환경과학회지
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• 제31권7호
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• pp.609-616
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• 2022

In this study, the effect of different reaction times for thermal-alkaline pretreatment on the solubilization and biogasification of polyhydroxybutyrate (PHB) were evaluated. Thermal-alkaline pretreatment tests were performed at 73 ℃ and pH 13 at 0-120 h reaction times. The mesophilic anaerobic batch tests were performed with untreated and pretreated PHB samples. The increase in the pretreatment reaction time results in a 52.8-98.8% increase of the abiotic solubilization efficiency of the PHB samples. The reaction time required to achieve solubilization efficiencies of 50%, 90%, and 95% were 10.5, 52.0, and 89.6 h, respectively. The biogasification of the untreated PHB samples achieved a specific methane production rate of 3.6 mL CH₄/g VSS/d and require 101.3 d for complete biogasification. The thermal-alkaline pretreatment significantly improved specific methane production rate (10.2-16.0 time increase), lag time (shortened by 76-81%), and time for complete biogasification (shortened by 21-83%) for the biogasification of the PHB samples when compared to those of the untreated PHB samples. The improvement was higher as the reaction time of the thermal-alkaline pretreatment increased. The findings of this study could be used as a valuable reference for the optimization of the biogasification process in the treatment of PHB wastes.

• 유기물자원화
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• 제5권2호
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• pp.47-56
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• 1997

피혁 제조시 발생되는 크롬을 함유한 피혁 고형폐기물인 shaving scraps의 단백질 자원화 가능성을 검토하기 위하여 알카리제로 MgO를 농도별로 처리하여 가수분해시켜 회수한 hydrolyzed protein의 특성은 다음과 같다. MgO 처리에 의한 shaving scrap의 알카리 가수분해방법에서 크롬이 불용화 되는 pH 8.0 이상을 유지하기 위해서는 MgO를 5% 이상 처리해야 하는 것으로 나타났으며, MgO 처리에 따른 alkaline condition하에서 shaving scrap의 용해도는 약 60% 수준으로서 낮았다. MgO 처리에 의해 shaving scraps으로 부터 회수한 hydrolyzed protein의 평균 분자량은 약 80~100 KD이었고, collagen protein을 구성하고 있는 glycine, alanine 및 proline이 대부분을 차지하고 있었으며, 산성 아미노산인 aspartic acid와 glutamic acid도 상당량 함유되어 있는 것으로 나타났다. 무기성분중 Mg, Ca 및 Na는 액체비료의 무기양분으로서는 다소 많은 양이 함유되어 있었으며, Cr은 약 30~40ppm으로서 원시료 (40,000~42,000ppm)에 비해 크게 감소되었다.

• Journal of Pharmaceutical Investigation
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• 제18권3호
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• pp.99-105
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• 1988

Inclusion complex formation of furosemide with ${\beta}-cyclodextrin({\beta}-CyD)$ in solid state was confirmed by X-ray diffractometry, IR spectroscopy and differential scanning calorimetry (DSC). The solid complexes of ${\beta}-CyD$ with furosemide in molar ratio of 2 : 1 were prepared by solvent evaporation method. The photodegradation of furosemide in alkaline solution under the light and the hydrolysis of furosemide in acidic solution were not inhibited by complex formation with ${\beta}-CyD$. However, the bioavailability of furosemide was improved by complex formation with ${\beta}-CyD$ after oral administration to rats.

• 한국수소및신에너지학회논문집
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• 제22권1호
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• pp.29-34
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• 2011

This study examined the effect of environmental variables, such as the NaOH concentration and solution temperature, on the rate of hydrogen generation from NaOH solutions through the corrosion of used aluminum cans as a potential candidate material for the safe and economic production of hydrogen. Corrosion of the used aluminum cans was promoted by increasing the NaOH concentration and solution temperature because of the loss of aluminum passivity. The measured rate of hydrogen generation from the NaOH solutions increased with increasing NaOH concentration due to the catalytic activity of NaOH in the hydrolysis process. However, at higher solution temperatures, the rate of hydrogen generation rate was less affected by the NaOH concentration than that at lower temperature.

• Bulletin of the Korean Chemical Society
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• 제26권7호
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• pp.1037-1043
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• 2005

Kinetic study on the cleavage of N-methylphthalamic acid (NMPA) in mixed acidic aqueous-acetonitrile solvent reveals the formation of both phthalic anhydride (PAn) (through O-cyclization) and N-methylphthalimide (NMPT) (through N-cyclization). The formation of NMPT varies from $\sim$20% to $\sim$3% with the increase in the content of acetonitrile from 2 to 70% v/v. Pseudo first-order rate constants for the formation of PAn are more than 4-fold larger than those for the formation of NMPT at 2% v/v $CH_3CN$ in mixed aqueous solvents. Pseudo first-order rate constants for alkaline hydrolysis of NMPT reveal a nonlinear decrease with increase in the content of $CH_3CN$ in mixed aqueous solvents.

• 한국환경농학회지
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• 제31권4호
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• pp.293-299
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• 2012

본 연구에서는 화학비료와 퇴비를 과다하게 투입하여 인산의 집적 및 유출 위험성이 높은 양파-벼 재배지와 시설재배지의 인산 집적 특성과 인산가수분해효소를 이용한 집적 인산의 수계에서의 생물이용가능성을 평가하였다. 수용성 인산 중 많은 부분의 유기태 인산이 주변 수계에 유출될 위험성이 높았지만 그동안 제대로 평가되지 못했다. 본 연구결과에서 alkaline phosphomonoesterase와 phosphodiesterase에 의해 이모작토양에서 DUP의 12, 24%가 시설재배지 토양에서 DUP의 18과 44%가 분해되는 것으로 나타났다. 토양에 축적된 유기태 인산중 orthophosphate monoester와 diester가 주로 인산분해효소에 의해 분해되어 농경지 주변 수계로 유출시 생물 이용 가능성이 큰 것으로 평가되었다. 따라서 수계에서 인산의 거동을 이해할 때 유기태 인산에 대한 충분한 고려가 필요할 것이다.

• 자원리싸이클링
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• 제11권2호
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• pp.14-19
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• 2002

PVC(polyvinyl chloride)sheet를 NaOH수용액 중에서 반응온도 $80~150^{\circ}C$, 반응시간 0~7시간으로 처리하여 가소제의 침출에 관해서 검토하였다. DOP의 가수분해에 의해서 생성된 프탈산 수율은 알카리촉매로써 NaOH농도의 증가와 온도의 상승으로 인해 증가하고, $150^{\circ}C$, 10M NaOH, 3시간이상에서 프탈산 수율은 거의 100%,에 달했다. 따라서 PVC sheet에 30% 포함되어져 있는 가소제는 알카리수용액 중에서 탈염화수소가 일어나기 이전에 가수분해되어졌다. 또한, PVC필름의 수열처리에서는 DOP의 가수분해로 인해 세공이 생성되었다.

• Journal of the Korean Wood Science and Technology
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• 제34권5호
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• pp.104-110
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• 2006

We investigated why aspen extractives are more resistant in kraft pulping than pine extractives. Residual extractives content in aspen kraft pulps were 0.5~1.1% compared with 0.1~0.2% in pine pulps. This different response arises from the different composition of extractives in wood chips. Resin acids in pine were almost completely removed in kraft pulping but those are not existence in aspen. Slower saponification of aspen steryl esters resulted from different chemical structure of aspen steryl esters. Main sterols in aspen steryl esters were 24-methyl cyclolanostenol which was highly resistant to alkaline hydrolysis with its characteristic steric hindrance. Sterols in aspen were not well removed in kraft pulping. The relative composition of sterol in aspen kraft pulps was increased with increasing pulping time. The presence of fatty acids in aspen kraft pulps is considered to unusual. Fatty acids in alkaline are supposed to be well ionized and removed well in the washing stage. Nevertheless, there were significant amount of fatty acids remaining in aspen kraft pulps.

• 한국펄프종이공학회:학술대회논문집
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• 한국펄프종이공학회 1999년도 Pre-symposium of the 10th ISWPC Recent Advances in Paper Science and Technology
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• pp.291-295
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• 1999

Coprinus cinereus 2249 that is a kind of basidiomycetes constitutively produced alkaline carboxymethyl cellulase (CMCase), filter paper cellulase (FPase) and xylanase. Crude enzymes prepared with optimal conditions showed higher FPase activity than CMCase activity. The FPase was most active at pH 9 at 50$^{\circ}C$. When applied on deinking of the old newsprint (ONP), it increases the freeness and brightness due to effect of hydrolysis at 0.1% enzyme concentration. Also, The physical properties of deinked pulp were improved.

• 약학회지
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• 제39권1호
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• pp.85-93
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• 1995

Acidic and alkaline hydrolysis of diol-type ginseng saponins produced a new glycoside, (20E)-ginsenoside Rh$_{3}$, and its stereoisomer (20Z)-, which were further subjected to alkaline by drolysis to give their aglycones, (20E)- and (20Z)-3$\beta$, 12$\beta$-dihydroxy-dammar-20(22),24-diene. The ratio of stereoisomeric mixtures was estimated to be ca. 5:1 from intensities of the peaks in $^{1}$H- and $^{13}$C-NMR spectra. The $^{1}$H- and $^{13}$C-NMR signals of ginsenoside Rh$_{3}$, which have remained unclarified, were completely assigned by the extensive application of modern NMR techniques.