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        검색결과 102

        61.
        1993.05 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The hydrolysis kinetics of 2-furyl chalcone derivatives [I]~[V] was investigated by ultraviolet spectrophotometery in 30% dioxane-H2O at 25℃ and the structure of these compounds were ascertained by means of ultraviolet, infrared and NMR spectra. The rate equations which were applied over a wide pH range(pH 1.0~12.0) were obtained. The substituent effects on 2-furyl chalcone derivatives [I]~[V] were studied, and the hydrolysis were facilitated by the electron attrecting groups. On the basis of the rate equation, substituent effect, general base effect and final product. the plausible hydrolysis mechaism was proposed: Below pH 4.0, it was only proportional to concentration of hydronium ion, at pH 4.0~9.0, neutral H2O molecule competitively attacked on the double bond. By contrast, above pH 9.0, it was proportional to concentration of hydroxide ion.
        4,000원
        62.
        1992.11 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The kinetics of the hydrolysis of indolylacrylophenone derivatives(IA) was investigated by ultraviolet spectrophotometry in 30% dioxane-H2O at 25℃ Rate equations were obtained over a wide pH range. On the basis of rate equation, general base catalysis and Hammett's plot, the mechanism of hydrolysis to the (IA) were proposed: Below pH 3.0, the hydrolysis of (IA) was proportional to hydronium ion concentration, between pH 4.0~9.0 neutral water molecule and hydroxide ion were added to carbon-carbon double bond and over pH 10.0 hydrolysis of (IA) was proportional to hydroxide ion concentration.
        4,000원
        63.
        1991.11 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The kinetics of hydrolysis of cinnamenylisophorone derivatives (rho-H, rho-Br, P-Cl, rho-OCH3) was investigated using ultraviolet spectrophotometry in 20%(v/v) dicxane-H2O at 25℃. A rate equation which can be applied over wide pH range (pH 1.0~13.0) was obtained. In order to investigate the substituent effects on cinnarnenylisophorone derivatives, Hammett constant was plotted. As the result, the rate of hydrolysis of cinnamenylisophorone derivatives was facilitated by electron donating group. Final products of the hydrolysis were benzaldehyde and isophorone, From the measurement of reaction rate constant according to pH changes, substituent effect, and final products, it was found that the hydrolysis of cinnarnenylisophorone derivatives was initiated by the neutral H2O molecule which does not dissociated at below pH 9.0, and in the range of pH 9.0~11.0 this reaction occurs by H2O or hydroxide ion competitively, but proceeded by the hydroxide ion above pH 11.0. On the basis of this kinetic study, the reaction mechanism of the hydrolysis of cinnamenylisophorone derivatives was proposed.
        4,000원
        64.
        1991.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The kinetic of hydrolysis for cinnamylidene aniline derivatives has been investigated by ultraviolet spectrophotometry in 20% (v/v) dioxane - H2O at 25℃. A rate equation which can be applied over wide pH range was obtained. The substituent effects on cinnamylidene aniline derivatives were studied and the hydrolysis was facilitated by electron attracting group. Final products of the hydrolysis were cinnamaldehyde and aniline. From the rate equation, substituent effect and final products, the hydrolysis of cinnamylidene aniline derivatives was initiated by the neutral molecule of H2O which does not dissociate at below pH 9.0~12.0, but proceeded by the hydrogen ion at above pH 5.0~9.0.
        4,000원
        65.
        1989.11 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The Kinetics of the Hydrolysis of benzalacetophenone derivatives has been investigated by ultraviolet spectrophotometry in 5% dioxane - H2O at 50℃. A rate equation which can be applied over wide pH range was obtained. The substituent effect on the hydrolysis of benzalacetophenone derivatives were facilitated by electron attracting groups. Based on the rate equation, substituent effect, general base effect, activation parameters and final product, the hydrolysis of benzalacetophenone derivatives seems to be initiated by the netural molecule of H2O which does not dissociate at below pH 9.0 but proceeded by the hydroxide ion at above pH 11.0. In the range of pH 9.0~11.0 these two reactions occur competitively.
        4,000원
        66.
        1989.11 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The rate constants of the hydrolysis of cinnamanilide derivatives were determined UV spectrometry in H2SO4 (5~20N), NaOH(5~11N) at 50~110℃ and rate equation could be applied over a strong acid and strong base were obtained. Final product of the hydrolysis was a cinnamic acid. The σ values obtained from the slope of linear plots of log kabs vs. Hammet tΣ constants were slightly negatives, Substituents on cinnamanilide showed a relatively small effect, with hydrolysis facilitated be electron donating group. Activation energy(Ea)was also calculated for the hydrolysis of the cinnamanilide. From this reaction rate equation, substituent effect and experimental of rate constants, that the hydrolysis of cinnamanillde was Initiated by the netural molecule of H2O which do not dissociate at strong acid, and proceeded by hydroxide ion at strong base.
        4,000원
        68.
        2018.09 KCI 등재 SCOPUS 서비스 종료(열람 제한)
        본 연구에서는 단백질 함량이 높은 들깨박을 기능성 식품소재로서의 활용가능성을 확인하기 위하여 단백질분해효소 및 한외여과를 이용하여 가수분해물과 펩타이드 분획을 제조하고 이들의 항산화 활성을 측정하였다. 먼저 들깨박단백질의 가수분해물 생산을 위한 최적 효소를 선정하기 위해 단백질분해효소 7종을 이용하여 효소 반응 후 가수분해도를 측정한 결과, flavourzyme이 가장 높은 가수분해율을 나타내었다. Flavourzyme에 의한 들깨박단백질 가수분해물을 얻기 위한 최적 조건은 pH 7.0, 50℃, 효소농도 10 unit, 가수분해시간은 4시간으로 결정되었다. 들깨박단백질 가수분해물을 한외여과 후 얻은 각 분획의 수율은 1 kDa 이하가 45.65%로 유의적으로 가장 높았으며, 그 다음으로5-10 kDa(16.45%), 10 kDa 이상(16.37%), 1-3 kDa(10.86%), 3-5 kDa(10.67%) 순으로 높았다. DPPH 라디칼 소거능은 효소가수분해물이, 환원력은 3-5 kDa 분획물이, superoxide dismutase 유사활성은 1 kDa 이하의 분획물이 가장 높은 활성을 나타내었다. 따라서 들깨박단백질로부터 생산된 가수분해물 및 펩타이드 분획은 각기 다른 항산화 활성 특성을 보여 기능성 식품 소재의 목적에 맞게 선택하여 활용할 수 있을 것으로 판단된다. 또한 향후 식품학적 기능성 평가가 이루어진다면 식품산업에서 다양한 식품재료로의 활용성이 확대될 수 있을 것으로 판단된다.
        69.
        2018.05 서비스 종료(열람 제한)
        최근 우리나라 서・남해안에 대량 유입되고 있는 괭생이모자반은 매년 그 양이 증가하고 있으며, 항해 및 양식시설 등에 피해를 주고 있다. 또한 막대한 비용 및 인력을 동원하여 수거한 후에도 그 처리에 어려움을 겪고있다. 우리나라 해안에 유입되는 양이 매년 증가하고 있어 괭생이모자반에 대한 적절한 처리방안 대책이 시급한 실정이다. 해조류는 바이오에너지 회수를 위한 바이오매스로 주목을 받아, 에너지 전환 공정에 대한 연구가 활발히 진행되고 있다. 괭생이모자반은 해조류 중 갈조류에 속하며 바이오매스로서의 잠재성이 높을 것으로 판단된다. 그러나 바다에서 수거/수확된 해조류에는 해수 속 염분이 일부 묻어 있을 것으로 사료되며, 이 단계에서 해조류 관리와 후속 공정과의 연구는 현재 미미하다. 이에 본 연구에서는 바다에서 수거된 괭생이모자반을 대상으로 수거직후 관리(세척여부)에 따라 바이오에너지 전환 공정 중 당 가수분해에 미치는 영향에 대하여 검토하였다. 세척시료와 미세척시료를 대상으로 강열감량 후 회분의 전기전도도 값을 측정한 결과, 미세척시료가 2.28 mS/cm로 세척시료보다 1.64배 높았으며, 이때 회분의 약 73%가 염분으로 나타났다. 세척과정을 반복적으로 실시하여 배출된 세척수의 전기전도도를 측정한 결과, 3회 세척 후 세척수 전기전도도는 1회 세척 후 결과 값의 88%가 감소하여, 해조류 표면에 묻은 염분은 반복되는 세척과정에서 상당부분 제거됨을 확인하였다. 세척여부는 당 가수분해 공정에도 영향을 미쳤으며, 특히 효소를 이용한 생물학적 가수분해 공정에 저해효과가 큰 것으로 나타났다.
        70.
        2018.04 KCI 등재 서비스 종료(열람 제한)
        Background: The demand of recycling renewable agricultural by-products is increasing. Radiation breeding is a method used to improve saccharification efficiency. Thus, we investigated the effect of gamma ray irradiation on the pretreatment and enzymatic hydrolysis of the stalks of Senna tora, an important medicinal plants. Methods and Results: S. tora seeds were irradiated with gamma ray at doses of 100, 200, 300, and 400 Gy. In the pretreated biomass, glucan and lignin content were higher in the M1 (1st generations of irradiation) S. tora stalks than in the M2 (2nd generations of irradiation) stalks, this can be explained by the higher degradation rate in M1. After oxalic acid pretreatment, the concentration of total phenolic compounds (TPCs) in the hydrolysate increased in the gamma ray treated seeds. The highest relative increase rate in crystallinity in the pretreated biomass was observed in M1-400 Gy and M2-100 Gy. The cellulose conversion rate was higher in M1 than in M2, except for 200 Gy. Conclusions: Gamma ray irradiation at an appropriate dose can be used to improve the efficiency of pretreatment and enzymatic hydrolysis, thereby increasing biomass availability.
        71.
        2017.11 서비스 종료(열람 제한)
        현재 국내에서 발생하는 유기성폐기물은 에너지화 정책에 따라 육상처리의 일환으로 혐기소화를 통한 바이오가스화 시설에서 처리 및 에너지원으로 전환되고 있다. 이러한 유기성폐기물 중 음식물쓰레기는 처리 단가가 높고, 바이오가스 회수 잠재력 또한 높아 바이오가스화 시설의 경제성을 높여줄 유용한 폐자원으로 여겨지고 있다. 하지만 국내에서 발생하는 음식물쓰레기의 평균 고형물함량(TS)은 18~20% 수준으로 혐기소화를 통한 바이오가스화를 위해서는 전처리가 필수적이다. 또한, 음식물쓰레기는 구성성분이 다양할 뿐만아니라 섬유질도 다량 포함하고 있어 혐기소화를 통해 바이오가스로 전환하기 위해서는 보통 30일 전후의 소화기간을 필요로 하고 있고, 특히 파쇄/선별의 단순 물리적 전처리만 거친 음식물쓰레기의 경우에는 30일 이상의 혐기소화 기간이 필요한 것으로 알려져 있다. 이에 본 연구에서는 사전 연구를 통해 도출된 음식물쓰레기 열가수분해 운전조건을 적용해 습식 혐기소화 반응조에 적합하도록 U원 구내 식당에서 발생한 음식물쓰레기를 전처리하였고, 이렇게 얻어진 음식물쓰레기 가용화물을 실험실 규모의 중온 단상 혐기소화 반응조에 투입해 일반적인 중온 이상습식 혐기소화 체류시간(35일)의 절반 수준인 18일의 체류시간으로 운전하는 조건에서 바이오가스 수율 및 반응조 안정성 등을 평가하고자 하였다.
        73.
        2017.05 서비스 종료(열람 제한)
        현재 국내에서 발생하는 음폐수의 해양투기 금지 및 음식물류 폐기물의 에너지화 정책에 따른 유기성 폐기물 육상처리의 일환으로 혐기소화를 통한 바이오가스화 시설이 지속적으로 설치 및 운영되고 있다. 그중에서도 음식물쓰레기는 처리 단가가 높고, 바이오가스 회수 잠재력 또한 높아 바이오가스화 시설의 경제성을 높여줄 유용한 폐자원으로 여겨지고 있다. 하지만 국내 발생 음식물쓰레기의 평균 고형물함량(TS)이 18~20% 수준으로 혐기소화를 통한 바이오가스화 이전에 전처리가 필수적이며, 단순 파쇄/선별을 통한 물리적 전처리만으로는 충분한 가용화가 어려운 부분이 있다. 이러한 유기성폐자원의 가용화를 위한 전처리 방법에는 가수분해/산발효를 통한 생물학적 처리, 산, 알칼리, 오존 등을 통한 화학적 처리, 초음파, 열, 압축 등에 의한 물리적 처리 등이 있는데 본 연구에서는 물리적 처리방법 중 하나인 열가수분해를 통한 음식물쓰레기의 가용화효율을 분석하였다. 이를 위해 1차로 물리적 파쇄/선별 처리한 음식물쓰레기에 대해 다양한 운전 조건(온도, 압력 변화)으로 열가수분해를 실시하여 각 운전조건별 음식물쓰레기 성상변화를 분석함으로써 음식물쓰레기 열가수분해를 위한 최적 운전조건을 도출하고자 하였다.
        74.
        2017.03 KCI 등재 서비스 종료(열람 제한)
        Recently, production of sewage and wastewater sludge have increased sharply with the population density and related industrial activity. As a result, studies of sludge treatment and reduction have been conducted and a pre-treatment method that uses thermal hydrolysis has emerged as a solution to this problem. To address problems with the thermal hydrolysis pre-treatment process, the deaeration and nitrogen recovery processes have been set up together, thus generating factors that inhibit dewaterability. In this study, the effect of pre-treatment, deaerated sludge on dewaterability-inhibiting factors (pH, temperature, aeration rate) was evaluated and alternative solutions were prepared. First, the dewaterability improvement effect increased rapidly at 190°C or higher when thermal hydrolysis pre-treatment was applied. Then, 1 L of thermal hydrolysis pre-treatment reactants at 190°C were injected into 1, 5, and 10 L/min air flows at 50°C, but no significant difference in capillary suction time (CST) or time to filter (TTF) was found. The dewaterability improved when the temperatures of the pre-treatment reactants varied between 30, 50, and 70°C under aeration at 5 L/min. However, when the pH was increased to 7, 9, or 11 at 5 L/min and 50°C, the dewaterability worsened by at least 10 times relative to the hydrolysis pre-treatment reactants. The zeta potential decreased from -30 mV to -50 mV as the pH increased. Thus, the stabilities and dispersities of the reactants increased due to the repulsive force of the particles. This was confirmed to be the cause of poor dewaterability. A coagulant can be used to solve to this problem, or the deaeration process can be placed after solid-liquid separation and the heat of thermal hydrolysis can be extracted via heat exchanger.
        75.
        2016.06 KCI 등재 SCOPUS 서비스 종료(열람 제한)
        본 연구는 폐기되는 돈혈을 식품소재로 활용하고자 단백 질 가수분해효소 5종을 처리하여 품질특성 변화를 조사하 였다. 그 결과 KMFP-15(E)로 가수분해할 때 pH 7.3, 총 고형분 함량 24.3 oBrix 및 유리아미노산 함량 4,944 mg%로 가장 높은 고형분 함량 및 유리아미노산 함량을 나타내었 다. KMFP-15(E) 농도에 따른 영향을 조사한 결과 처리농도 가 증가함에 따라 총 고형분 함량 및 유리아미노산이 증가 하였으며, 유리아미노산은 KMFP-15(E) 0.2% (w/v)첨가구 에서 7,224 mg%로 0.3% (w/v)첨가구와 유의적인 차이를 나타내지 않아 0.2% (w/v)로 설정하였다. KMFP-15(E)의 가수분해 시간에 따라 유리아미노산 함량은 4시간에서 7,404 mg%로 가장 높게 나타났으며, 시간이 경과할수록 감소하는 경향을 보여 최적 가수분해시간은 4시간으로 설 정하였다. 상기 설정된 가수분해 조건을 통해 제조된 돈혈 분말(PBHP)에는 조단백질 및 아미노산과 철분, 칼륨, 아연 등 다량의 무기질이 함유되어 있는 것으로 나타났으며 특 히, 철분의 함량은 1,983 mg%로 높게 나타나 식품소재로 활용 가능한 것으로 나타났다. 이상의 결과 폐기되는 돈혈 의 활용방안으로 다양한 가수분해조건중 효소 KMFP- 15(E) 0.2% (w/v)를 첨가하여, 4시간에서 가수분해 하였을 때 전반적 품질 특성이 가장 우수하여 향후 돈혈을 이용해 단백질 보충, 아미노산소재 및 철분강화제 등의 식품 및 의약품 소재로의 고부가가치 창출이 가능할 것으로 판단되 었다.
        76.
        2016.01 KCI 등재 서비스 종료(열람 제한)
        We investigated optimal conditions for the hydrolysis of Laminaria japonica using a single enzyme such as Celluclast 1.5 L, Saczyme, and alginate lyase, for the production of reducing sugar. Redesigned experimental conditions including the optimal conditions determined for the single enzyme were proposed, and the hydrolysis of Laminaria japonica was also performed with a mixture of enzymes. The reducing sugar yield with the mixed enzymes was lower than that with Celluclast 1.5 L, which showed the highest efficiency among the enzymes used. Considering the reducing sugar yield and economics, it would seem that hydrolysis by mixed enzymes had no advantage. The coefficient of determination (R2) of Y1 (the yield of reducing sugar by Celluclast 1.5 L) was 0.89. The P value of Y1 was < 0.001, indicating statistical significance. By the response surface methodology (RSM), the optimum reaction conditions for hydrolysis of Laminaria japonica by Celluclast 1.5 L were determined to be enzyme of 8.0%, a reaction time of 26.4 h, a pH of 4.0, and a temperature of 42.6oC, resulting in the production of 117.7 mg/g-Laminaria japonica.
        77.
        2015.05 서비스 종료(열람 제한)
        Slaughter of cattle, pigs, and chickens has increased continuously. In particular, slaughter of chickens has been grown up about 150% in 2010 than that in 2003, that is approximately 120,000 tons. All of them are underwent consigned treatment even though those can be used as a resource and an energy source. With this regards, THR (Thermal Hydrolysis Reaction) leads to reduce water content drastically (<30% in sludge cakes). In addition, Dehydrated solid would be re-used as solid fuels (SRF) as well. In this study, We have applied THR to a plant (10 ton/day) on the basis of our lab and pilot results. Water content of sludge cakes showed with a ranges of 30 to 40% after solid-liquid separation. Dairy SRF produced 1.5 ton/day and its heat capacity for SRF has 6,500 kcal/kg. This gave the steam produced about 12 ton/day throughout the plant operation, suggesting that THR system would expect energy savings.
        78.
        2014.12 KCI 등재 서비스 종료(열람 제한)
        In this study, microcrystalline cellulose, which is a cell wall polysaccharide commonly contained in sea algae (brown algae, red algae and green algae), is used in substitution for cellulose and is hydrolyzed with seven enzymes available in the market. The seven enzymes selected are Viscozyme® L, Celluclast® 1.5 L, Saczyme, Novozym® 33095, Fungamyl® 800 L, Driselase® Basidiomycetes sp., and Alginate Lyase. To maximize the production of the reducing sugar by hydrolysis with each enzyme, we optimized the quantity of enzymes, reaction time, pH, and reaction temperature as four independent variables, and the reducing sugar production rate as a dependent variable, utilizing response surface methodology (RSM) to optimize the enzyme hydrolysis reaction conditions. Among the tested enzymes, the production rate of reducing sugar by Celluclast® 1.5 L was the highest. Hence, the predicted optimum conditions (8.5 % enzyme, reaction time 27.6 h, pH 4.1 and reaction temperature 44.1oC) were directly applied to Laminaria japonica and proved the predicted optimum conditions with experiments. Under the optimum conditions, the sugar yield of 137.6 mg/g-Laminaria japonica (experimental value) was obtained.
        79.
        2014.10 KCI 등재 서비스 종료(열람 제한)
        This study investigated the optimal sequential hydrolysis conditions by comparing with reducing sugar yield ofsequential hydrolysis of Laminaria japonica processing residue. After acid-catalyzed hydrothermal hydrolysis, sequentialenzymatic hydrolysis was performed with single enzymes such as Celluclast® 1.5L, Saczyme, and Alginate Lyase, andtheir mixture. As a result, the yield of reducing sugar by sequential hydrolysis with the mixed enzymes was the highest,but there would be an economical problem with excessive enzyme loading. Therefore, considering the reducing sugaryield and economics, it is thought that hydrolysis by the mixed enzymes has no advantage, thus, using the Celluclast®1.5L in the sequential hydrolysis was practically more appropriate. The optimal sequential hydrolysis conditions ofLaminaria japonica processing residue were determined to be 8% v/w of enzyme injection, 42.6oC of reaction temperature,pH 4.1, and 26 hours of reaction time after acid-catalyzed hydrothermal hydrolysis (0.108 N-HCl, 144oC of reactiontemperature, and 22 minute of reaction time).
        80.
        2014.02 KCI 등재 서비스 종료(열람 제한)
        This study was carried out to investigate change of ginsenoside contents in red and fresh ginseng according toroot part and age by hydrolysis. Neutral total ginsenoside contents by hydrolysis in 6-year main root and lateralroot were significantly increased than those by non-hydrolysis, as 41.6 and 32.8%, respectively. However, there wasno significant difference in red ginseng. In fresh ginseng, ginsenoside contents of the protopanaxatriol group such as Re, Rf,Rg₁, Rg₂, and Rh₁ were not significantly different, but Rb₁, Rb₂, Rb₃, Rc, and Rd showed significant difference. The increaserate of neutral total ginsenoside content by hydrolysis was higher in epidermis-cortex than stele. Also, the neutraltotal ginsenoside content was fine root>rhizome>lateral root>main root, respectively. While there was no tendencytowards the increase of ginsenoside by hydrolysis with the increase of root age in fine root and rhizome, there was significantdecrease in main root and lateral root.
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