• 펄프종이기술
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• 제46권6호
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• pp.1-7
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• 2014

Dissolving part of xylan and lignin in lignocellulosic biomass by base can be used as pretreatment technique. Cork oak was pretreated with sodium hydroxide solution and the pretreatment effects were evaluated with two critical factors - NaOH concentration and pretreatment temperature. Some of xylan and lignin were removed by base pretreatment. At $90^{\circ}C$ and 13% NaOH pretreatment, 22.0% of lignin and 78.8% of xylan removed by base treatment. Enzymatic hydrolysis of cork oak which was pretreated at higher temperature or concentration was further improved. After pretreatment of cork oak with 13% NaOH at $90^{\circ}C$, the conversion rate of cellulose to fermentable sugars were reached up to 91.3%. At ethanol fermentation with enzymatic hydrolysate from different pretreatment conditions, all enzymatic saccharification liquids were well fermented by Saccharomyces cerevisiae.

• 산업기술연구
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• 제39권1호
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• pp.7-14
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• 2019

Carbon nanotubes (CNT) on metal substrates are definitely beneficial because they can maintain robust mechanical stability and high conductivity between CNT and metal interfaces. Here, we report direct growth of CNT on Ni-based superalloy, Inconel 600, using thermal chemical vapor deposition (CVD) with acetylene feedstock in the growth temperature range of $400-725^{\circ}C$. Furthermore, we studied the effect of substrate pretreatment on the growth yield enhancement and growth temperature decrease of CNT on Inconel 600. Activation energy (AE) for CNT growth was estimated from the CNT height change with respect to the growth temperature. The AE values significantly decreased from 205.03 to 24.35 kJ/mol by the pretreatment of thermal oxidation of Inconel substrate at $725^{\circ}C$ under ambient. Higher oxidation temperature tends to have lower activation energy. The results have shown the importance of pretreatment temperature on CNT growth yield and growth temperature decrease.

• 한국토양비료학회지
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• 제47권2호
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• pp.127-132
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• 2014

The effect of thermal pretreatment conditions on hydrolysis characteristics of dairy manure and sawdust mixtures has been evaluated. Thermal pretreatment temperature varied between 35 and $120^{\circ}C$ and the period of the treatment changed between 30 and 1440min (24h). As thermal pretreatment temperature and duration increased, organic material solublization rates were improved. Maximum solubilizations of chemical oxygen demand (SCOD), carbohydrates, and volatile fatty acids(VFAs) were observed when dairy manure treated for one day at $120^{\circ}C$. Although one day treatment duration at $120^{\circ}C$ showed the highest SCOD, soluble carbohydrates, and VFAs concentration, its hydrolysis rate was only about 12%. The results reveal that the thermal pretreatment conditions tried in this study are not enough to solubilize the organic matter contained in dairy manure and sawdust mixtures. In order to maximize hydrolysis performance, the further research needs to determine the factors influences on organic material solubilization in addition to thermal pretreatment temperature and duration.

• 식물조직배양학회지
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• 제28권5호
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• pp.263-271
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• 2001

고추의 약을 배지에 치상한 후 4$^{\circ}C$와 32$^{\circ}C$의 온도 전처리가 소포자의 활력, 초기분열 및 소포자 배 발생에 미치는 영향을 조사하였다. 활력 있는 소포자의 비율은 모 식물에서 채취하여 치상할 당시에는 62~64%정도였으나 치상 후 온도처리 기간 중에는 매우 급속하게 저하되었다. 소포자의 활력은 4$^{\circ}C$ 처리에 비해 32$^{\circ}C$ 처리 시에 더욱 심하게 감소하였으며 배양 9일이 되면 온도처리와 관계없이 활력 있는 소포자가 거의 없었다. 치상 당시의 소포자는 대부분이 후기 1핵성 소포자기였으며 배양 2일 후부터 핵이 소실된 무핵 소포자들과 함께 다양한 유형의 다핵 소포자들이 나타났다. 배 발생적 소포자의 비율은 고온처리에서 높았으나 균등분열에 의한 동형2핵 소포자의 출현에는 온도처리에 따른 차이가 크지 않았으며 다핵 소포자들은 균등 또는 불균등 분열에 의해 생겨났다. $25^{\circ}C$와 32$^{\circ}C$ 처리에서는 배양 2일 후에 이미 퇴화 소포자들이 50% 이상이 되었는데 4$^{\circ}C$ 처리에서는 14일 동안 대부분의 소포자들에서 핵이 완전하였다. 소포자 배의 발생은 4$^{\circ}C$ 처리에 비해 32$^{\circ}C$ 처리에서 높았으며 가장 효과적인 고온처리 기간은 4일이었다. 이에 비해 4$^{\circ}C$ 처리에서는 2일 처리가 가장 효과적이었으며 처리기간이 길어질수록 소포자 배의 발생이 감소되었다.

• Bulletin of the Korean Chemical Society
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• 제34권2호
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• pp.379-383
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• 2013

For the production of ethanol from freshwater cyanobacteria, a new pretreatment method using supercritical fluid was introduced. In this study, it was found that the supercritical fluid could penetrate inside the cell wall and help to liberate starch from cyanobacterial cells which resulted in the increase of the efficiency of ethanol production. For Microcystis aeruginosa, supercritical fluid pretreatment increased the amount of ethanol produced from cyanobacteria from 1.53 g/L to 2.66 g/L. For Anabaena variabilis, the amount of ethanol was increased from 1.25 g/L to 2.28 g/L. With use of supercritical fluid pretreatment, the efficiency of the process to obtain higher ethanol yields from freshwater cyanobacteria was improved upto 80%. The optimum temperature and pressure conditions for supercritical fluid pretreatment were determined as the temperature of $40^{\circ}C$ and the pressure of 120 atm. This study demonstrates the feasibility of using supercritical fluid pretreatment for ethanol production using freshwater cyanobacteria.

• 한국염색가공학회지
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• 제8권3호
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• pp.59-65
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• 1996

Cotton fabrics were treated by low temperature plasma and/or cellulase, and its physical and dyeing properties were investigated. All the pretreatments of the cotton with low temperature plasma of oxygen, nitrogen and argon slowed down the rate of weight loss of cotton in cellulase solution. Plasma pretreatment did not show any strength retention effect on cotton fiber in the subsequent cellulase treatment. Pretreatment of cotton with low temperature oxygen plasma decreased the rate of dyeing in direct dye bath, while cellulase or plasma/cellulase pretreatment increased the rate. Equilibrium dye uptake of cotton was not changed greatly by the pretreatments except the normal untreated cotton showed more or less high uptake. The pretreatment of cellulase with a water-soluble carbodiimide reduced the enzymatic activity, and did not show any strength retention of cotton in enzymatic weight loss.

• 동아시아식생활학회지
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• 제7권1호
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• pp.57-63
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• 1997

In order to use leaf mustard Dolsan food preservative ingradient acidity, antimicrobial activity and colors were investigated during pretreatment of leaf mustard Dolsan. pH was remarkably decreased after 8 hours to pretreatment(extracted on shaking) of leaf mustard Dolsan, and no changes were observed after that time. pH of leaf part was higher than stalk after 8 hours storage. Titratable acidity was opposite tendency to the pH. pH was gradually decreased than initial stage during pretreatment of leaf mustard Dolsan at 30, 40 and 5$0^{\circ}C$. After 16 hours pretreatment, the higher pretreatment temperature was, the higher pH was, but after pretreatment for 48 hours, pH of sample pretreated at 5$0^{\circ}C$ was lower than that of sample pretreated at 40 $^{\circ}C$. Antimicrobial activity of leaf mustard Dolsan extract pretreated at 3$0^{\circ}C$ was the strongest of the samples pretreated at 30, 40 and 5$0^{\circ}C$, and that of stalk part was stronger than that of leaf part. L and time. L and b value was higher in the order of samples pretreated at 40, 50 and 3$0^{\circ}C$, and the lower pretreatment temperature was, the higher a value was. L value of stalk part was higher than that of leaf part, but a and b value of leaf part was higher than that of stalk part.

• 한국대기환경학회지
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• 제18권3호
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• pp.205-212
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• 2002

The catalytic combustion of benzene, toluene and xylene over Pt-based catalyst was investigated in a fixed bed flow reactor system with atmospheric pressure to recycle the waste industrial catalyst for the processes of removing volatile organic compounds. According to the pretreatment condition, the properties of the waste Pt-based catalyst were characterized by XRD (X-ray diffraction) and BET (Brunauer-Emmett-Toller). In the carte of air pretreatment, 20$0^{\circ}C$ was found to be optimal, and increasing pretreatment temperature resulted in the reduction of the catalytic activity. When Pt-based catalyst pretreated at 20$0^{\circ}C$ by alto was retreated by hydrogen, the catalytic activity increased by increasing treatment temperature. In the case of HNO$_3$aqueous solution pretreatment, the catalytic activity decreased by increasing the concentration of HNO$_3$aqueous solution. The catalytic activity was seen to observe the following sequence : benzene > toluene > xylene.

• 유기물자원화
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• 제19권3호
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• pp.79-89
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• 2011

강원도에서 확보한 폐옥수수대는 글루칸 44.6 %, 자일란 23.8 %, 리그닌 23.8 %, 회분 4.5 %, 기타 8.1 %로 이루어져 있다. 묽은 황산을 이용한 전처리 공정을 통계적 방법인 완전요인배치으로 분석한 결과 온도가 가장 중요한 변수로 나타났으며 자일로스 수율 기준으로 처리 시간과 농도에 비해 각각 3.5배와 3.2배 큰 영향력을 보여주었다. 포도당 수율에 대해서도 온도의 영향력이 가장 큰 것으로 나타났지만 포도당 수율은 전체적으로 5 % 이내의 낮은 값을 나타내었다. 마이크로웨이브와 초음파 각각을 이용한 전처리 공정은 그 효과가 크지 않거나 미미하였으나 묽은 황산처리와 복합적으로 적용했을 때는 그 효과는 상당히 큰 것으로 나타났다. 특히 마이크로웨이브와 묽은 황산처리를 순차적으로 적용했을 때 자일로스 수율은 2배 넘게 향상되었다. 향후에는, 다양한 복합 전처리 공정에 대한 심도있는 연구와 더불어 전처리와 효소당화 공정의 최적화에 대한 연구를 수행할 계획이다.

• KSBB Journal
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• 제29권1호
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• pp.22-28
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• 2014

In this study, we investigate the effect of pretreatment method on lipid extraction from Enteromorpha intestinalis using physical, thermo-chemical, and enzymatic process such as ultrasonication, high temperature treatment, freezing, microwave irradiation, osmotic shock, pH shock, homogenizing, and enzymatic treatment. In pretreatment with separated lipid extraction, the high extraction yield was obtained by high temperature treatment ($121^{\circ}C$ for 5 min) with 0.1 N HCl, which is 1.4 times higher than that of control. In pretreatment with direct lipid extraction, the high extraction yields were obtained by 0.1 N HCl pretreatment, microwave irradiation (700W, 1 min with twice), and 10% NaCl pretreatment, which is 1.45 times higher than that of control. In the result of enzymatic pretreatment with 17 kinds of enzymes, Cellic CTec II showed the high extraction yield of 5.3%, and which is 1.9 times higher than that of control. Moreover, the extraction yield was increased by the increase of enzyme amounts. In 10% enzyme amount, about 5.8% yield was obtained.