• 공업화학
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• 제16권4호
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• pp.519-526
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• 2005

소다석회 조성의 폐 유리를 발포유리의 원료로 활용하기 위해 폐유리의 가수분해를 시도하였다. 소다석회유리 조성으로 만들어진 판유리 및 병 유리 등은 공히 가압 하에서 증기상의 물 또는 액체상의 물에 의해 효율적으로 가수분해가 진행되었다. 최적의 가수분해의 조건은 공히 $250^{\circ}C$, 2 h이었으며 이 조건하에 얻어진 수화유리의 함수율은 발포유리의 원료유리로서 발포화가 가능한 7.85~10.04%였다. 수식제인 Na성분은 액상의 물에 의한 가수 분해에 효율적이며 유시시료에 대한 중량비로서 0.04첨가 시 가장 높은 함수율을 지닌 수화유리가 얻어졌다.

• Korean Chemical Engineering Research
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• 제51권1호
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• pp.106-110
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• 2013

거대 해조류인 다시마의 가수분해에 적합한 이온성 액체를 선정하기 위하여 20종의 이온성 액체를 실험에 사용하였다. 이 중 환원당의 생성능이 우수하다고 판단되는 3종의 이온성 액체 촉매(1-ethyl-3-methylimidazolium tetrafluoroborate, n-butyl-4-methylpyridinium tetrafluoroborate, n-methylmorpholine [$HSO_4$])를 선정하였다. 이들 이온성 액체를 대상으로 반응온도, 촉매량, 반응시간에 따른 영향을 조사하였다. 3종의 이온성 액체 촉매 모두에서 반응온도가 $121^{\circ}C$가 되어야 다시마의 가수분해가 일어나는 것으로 확인되었다. 3종의 모든 이온성 액체 촉매에서 반응시간이 지남에 따라 선형적으로 증가되는 경향을 보였다. 1-Ethyl-3-methylimidazolium tetrafluoroborate를 촉매로 사용한 경우에서는 90분에는 약 6.2 g/L, n-butyl-4-methylpyridinium tetrafluoroborate는 6.4 g/L, n-methylmorpholine [$HSO_4$]는 6.0 g/L의 환원당을 얻을 수 있었다. 이로부터 이온성 액체를 촉매로 이용하여 해조류로부터 당의 생산가능성을 확인하였다.

• 한국토양비료학회지
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• 제48권6호
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• pp.602-609
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• 2015

In order to enhance a biogas production by the hydro-thermal pre-treatment of piggery manure, the effects of hydro-thermal reaction temperature at thermal hydrolysis of piggery manure on the methane potential and anaerobic biodegradability of thermal hydrolysate were analyzed. The increase of hydro-thermal reaction temperature from $170^{\circ}C$ to $220^{\circ}C$ caused the enhancement of hydrolysis efficiency, and most of organic matters were present in soluble forms. However, the methane potentials ($B_u-TCOD$) of hydrolysate were decreased from 0.239 to $0.188Nm^3kg^{-1}-TCOD_{added}$ by increasing hydro-thermal reaction temperature from $170^{\circ}C$ to $220^{\circ}C$, and also the anaerobic biodegradability (DTCOD) decreased from 74.6% to 58.6% with increase of hydro-thermal reaction temperature. The increase of hydro-thermal reaction temperature from $170^{\circ}C$ to $220^{\circ}C$ resulted in the decrease of easily biodegradable organic matter content, while persistent organic matter contents increased.

• Journal of the Korean Wood Science and Technology
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• 제37권6호
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• pp.578-584
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• 2009

백합나무 목분으로 고농도 단당류를 생산하기 위하여 진한 황산을 사용하는 산 가수분해 특성을 연구하였다. 목분과 황산의 비율을 달리하거나 2차 가수분해의 온도와 시간을 달리하여 당화액 제조의 최적 조건을 탐구한 결과, 1차 가수분해의 목분과 72% 황산 비율은 1 : 2.61(w/w)였으며, 2차 가수분해 온도와 시간은 $105^{\circ}C$에서 70분 가수분해 조건이었다. 이때 생성된 당화액의 농도는 glucose가 44.8 g/L였고 xylose는 25.2 g/L였다. 산 가수분해를 통하여 얻어진 당화액을 발효할 때 발효 저해물질로 알려진 furfural, 5-HMF (5-hydroxymethylfurfural), 저분자량 페놀성 화합물들이 생성되었는데 furfural과 5-HMF는 2차 가수분해 온도가 높아짐에 따라, 그리고 반응시간이 길어짐에 따라 생성량이 증가하였다. $110^{\circ}C$ 2차 가수분해 조건에서 반응시간이 40분을 지남에 따라서 xylose농도는 감소하였고 glucose 농도는 일정하였는데, xylose는 생성속도보다 furfural로 전이 속도가 더 빠른 것으로 생각되고, glucose의 경우 생성속도와 5-HMF로 전이속도가 비슷하여 농도가 일정하게 나타났다.

• 한국염색가공학회지
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• 제7권4호
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• pp.61-73
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• 1995

Inorganic salts have negative or positive effects on the rates of many chemical reactions and also the rates of acidic and alkaline hydrolysis of carboxylic esters. The direction of salt effects on the hydrolysis of ester depends on the charge of esters. It is expected that the rate of the alkaline hydrolysis of Poly(ethylene terephthalte)(PET), polymeric solid carboxytic polyester with carboxyl end group at the polymer end, is also influenced by inorganic salts. In the present work, to clarify the effect of divalent cations on the alkaline hydrolysis of PET, many salts with divalent cations like $MgCl_{2},CaCl_{2},SrCl_{2},BaCl_{2},$ were added to the aqueous alkaline solutions. Then PET was hydrolyzed with aqueous NaOH solution having many salts under various conditions. Some conclusions obtained from the experimental results were summarized as follows. Many salts with various divalent cations increased or decreased the reaction rate of alkaline hydrolysis of PET depending on their electrophilicity, hydration property, ability of ion pair formation, solubility, and the degree of interactions between divalent cations and anions, etc. The hydrolysis was interrupted in the order of $Ca^{+2} and was generally accelerated in the order of $Ba^{+2}. It was inferred from the increase in ΔS$^*$and the decrease in the ΔG$^*$that the divalent cations $Sr^{+2}$ and $Ba^{+2}$attracted by PET increased the collision frequency between carbonyl carbon and $OH^{-}$ion and then accelerated the reaction rate. $Mg^{+2}$and $Ca^{+2}$decreased the reaction rate because of their strong interaction with $OH^{-}$.

• 한국생물공학회:학술대회논문집
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• 한국생물공학회 2005년도 생물공학의 동향(XVI)
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• pp.360-363
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• 2005

This study was a method that used a hydrolysis for increasing the efficacy of alcohol decrease from Hovenia dulcis extract. The best pH was 2.0 to obtain a maximum activity at fixed reaction temperature and time. At pH 2.0, reaction temperature $80^{\circ}C$ and reaction time 4 hr gave the highest activity which was 124.2% of control. This is very simple and efficient method to increase the efficacy of alcohol decrease from Hovenia dulcis extract. The mechanism that increases the efficiency of alcohol decrease be examined through hydrolysis.

• KSBB Journal
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• 제13권1호
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• pp.20-25
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• 1998

Optimum conditions of the cellulose-hydrolysis reaction with mixed enzymes(cellulase extracted from Penicellium funiculosum mixed with $\beta$-glucosidase extracted from Almod) were investigated to increase the production of glucose from cellulose. Experimental result showed that optimum conditions fro pH, activity ratio of $\beta$-glucosidase to cellulase, concentration of mixed enzymes, concentration of cellulose as a substrate, and temperature range were 4.2, 0.4, 0.8, U/mL, 40 g/L, and 37$\pm$3$^\circ C$, respectively. In these conditions, quantities of glucose productions by using mixed enzymes were larger than those by using cellulase at optimum conditions.

• 한국생물공학회:학술대회논문집
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• 한국생물공학회 2005년도 생물공학의 동향(XVII)
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• pp.530-534
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• 2005

This work was a method that used an acid hydrolysis for increasing the efficacy of decreasing alcohol concentration from Hovenia dulcis extract. The best pH was 2.0 to obtain a maximum alcohol dehydrogenase activity at fixed reaction temperature and time. At pH 2.0, reaction temperature $80^{\circ}C$ and reaction time 4hr gave the highest activity which was 124% of control. The bioactive compound, (+)-dihydromyricetin, content increased to 30% after acid hydrolysis. This is very simple and efficient method to increase the efficacy of decreasing alcohol concentration from Hovenia dulcis extract. The mechanism that increase the efficiency of alcohol decrease be examined through hydrolysis.

• 한국응용과학기술학회지
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• 제25권1호
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• pp.48-51
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• 2008

Dipalmitoyl phosphatidyl choline and p-nitrophenyl palmitate were directly sonicated in acidic water for 6 minutes to give clear stock solutions. The catalytic hydrolysis of p-nitrophenyl palmitate was studied at $30-50^{\circ}C$ in the presence of unilamellar vesicle and mixture of unilamellar and multilamellar aggregates. The difference of reaction rate between unilamellar and multilamellar was observed. The rate of unilamellar reaction compared to the rate of mixture reaction showed more catalytic effect. The phase transition temperature of vesicle was measured at $37-44^{\circ}C$.

• Bulletin of the Korean Chemical Society
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• 제28권11호
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• pp.2029-2033
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• 2007

Hydrotalcite, layered double hydroxides (LDH), with hexagonal morphology has been rapidly synthesized by microwave reaction within 1 hour by urea hydrolysis from homogeneous solution. Different synthesis parameters, Mg/Al molar ratio, microwave reaction temperature and microwave power were systematically investigated. Pure hydrotalcite phase was obtained for Mg/Al ratios of 2:1 and 3:1, and higher reaction temperature gave higher crystallinity. The hydrotalcite synthesized at 600W power shows the highest crystallinity and more homogeneous crystal size distribution. The hydrotalcite samples were characterized by powder X-ray diffraction (XRD), simultaneous thermogravimetric/differential thermal analysis (TG/DTA), Fourier Transform Infrared (FT-IR) and Scanning electron micrograph (SEM).