• 제목/요약/키워드: ${\beta}$-mixing

검색결과 131건 처리시간 0.02초

폐지의 유가식 동시당화발효에 의한 에탄올 생산 (Fed-Batch Simultaneous Saccharification and Fermentation of Waste Paper to Ethanol)

  • 권정기;문현수;김준석;김승욱;홍석인
    • KSBB Journal
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    • 제14권1호
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    • pp.24-30
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    • 1999
  • Brettanomyces custersli를 이용하여 신문지의 유가식 동시 당화발효에 의한 에탄올 생산에 대한 연구를 수행하였다. 유가식 동시당화발효에 의한 에탄올 생산을 효과적으로 수행하기 위한 초기 기질 투입 농도는 8%(w/v)이었고 효소의 비용을 감안한 최적 효소 농도는 cellulase의 경우 30EPU/g cellulase, $\beta$-glucosidase와 cellulase의 부피가 0.1(활성비 1.05)이었다. 앞에서 결정된 초기 조건들을 가지고 교반식 반응기에서 수행된 유가식 동시당화발효는 26.8g/L의 에탄올을 생산성에서 회분식 동시당화발효보다 약 2배의 값을 나타내었다.

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투명 결정화유리의 구조에 관한 연구 (Studies on the Structure of Transparent Glass Ceramics)

  • 박용완;박원규;김대혁
    • 한국세라믹학회지
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    • 제27권2호
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    • pp.288-296
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    • 1990
  • Parent glasses for the experiments were prepared to be ratio of Li2O : Al2O3 : SiO2=4.5 : 25 : 70.5 as basic components, and TiO2 and ZrO2 in the mixing ratio of 1 : 1 were added as the nucleating agents, whose contents were increased in each sample. DTA, XRD, SEM, IR were observed, and thermal expansion and transmissivities were measured for the crystallized samples under the controlled heat-treatments. The transformation temperatures and the dilatometric softening temperatures in thermal expansion curves, and also the exothermic peaks in differential thermo-analytical curves were shifted to lower temperature. The crystal phase deposited through the heat-treatment was identified as ${\beta}$-quartz solid solution with XRD and IR analysis. The crystalline phases in oopactified samples were ${\beta}$-spodumene coexiting with ${\beta}$-quartz solid solution. The samples having more than 3% nucleating agents were transparent. The crystallized grain sizes were ranged 0.05 to 0.1$\mu\textrm{m}$. The crystallized transparent samples were exceeded 85% in the transmissivity.

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Chiral Separation of Arylalcohols by Capillary Electrophoresis Using Sulfonated β-Cyclodextrin and Ag Colloids as Additives

  • Choi, Seong-Ho;Noh, Hyen-Ju;Lee, Kwang-Pill
    • Bulletin of the Korean Chemical Society
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    • 제26권10호
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    • pp.1549-1554
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    • 2005
  • Chiral separation of arylalcohols such as 1-phenyl-1-propanol, 1-phenyl-2-propanol, and 2-phenyl-1-propanol by capillary electrophoresis was studied using sulfonated $\beta$-cyclodextrin (CD) as a chiral selector and Ag colloids as an additive. The optimum separation condition of arylalcohols was found to be the chiral selector concentration of 6.5 mM, applied voltage of 15 kV, and pH of 7.0. In order to improve chiral separation, an Ag colloid was mixed with a running buffer. The resolution in the Ag colloid-mixed running buffer was considerably superior to that obtained with the sulfonated $\beta$-CD alone. The molar ratio of sulfonated $\beta$-CD to Ag colloid, which is one of critical parameters affecting resolution, was found to be optimum at 65 : 1. In order to elucidate the resolution mechanism, an inclusion-complex of the arylalcohols with sulfonated $\beta$-CD was prepared by mixing and shaking in solution, and then characterized by cyclic voltammetry (CV). The inclusion mechanism was also discussed using experimental results.

Agrobacterium spp. R259 KCTC 10197BP로부터 생산된 ${\beta}-glucan$ 고함유 식빵 반죽의 특성 (Baking Qualities of Bread Dough Substituted with High Amount of ${\beta}-Glucan$ from Agrobacterium spp. R259 KCTC 10197Bp)

  • 강은영;양윤형;오상희;이정희;김혜영;김미경;조한영;김미리
    • 한국식품과학회지
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    • 제38권3호
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    • pp.348-354
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    • 2006
  • 기능성 식품소재인 ${\beta}-glucan$을 식빵재료의 10, 20 및 30% 첨가하여 제조한 반죽의 이화학적 특성을 분석하였다. ${\beta}-Glucan$ 첨가량이 많을수록 반죽형성시간이 증가한 반면 발효에 걸리는 시간은 단축되었다. 반죽의 발효팽창력은 ${\beta}-glucan$ 20% 첨가까지 ${\beta}-glucan$ 첨가량이 증가할수록 증가하였고 ${\beta}-glucan$ 30% 첨가시에는 유의적으로 감소하였다. 반죽의 pH는 대조군의 경우 발효과정을 거치면서 낮아지는 경향을 나타내었으나 ${\beta}-glucan$ 첨가군은 다소 증가하였다. 반죽의 물성 중 탄력성은 ${\beta}-glucan$의 첨가량이 증가함에 따라 증가하고 경도는 감소하였다. 검성은 ${\beta}-glucan$ 10 및 20% 첨가군의 경우 대조군과 차이가 없었고 ${\beta}-glucan$ 30% 첨가군은 유의적으로 낮았다. 발효과정이 진행됨에 따라 반죽은 탄력성, 검성, 경도 및 응집성이 모두 감소하는 경향을 보였으나, ${\beta}-glucan$ 첨가에 따른 유의적인 변화는 없었다. Amylogram에서 호화개시온도와 최고점도에 달하는 온도가 모두 높아져 ${\beta}-glucan$이 호화를 지연시켰으며, setback과 consistency는 감소하여 ${\beta}-glucan$이 식빵노화를 지연시켜 줄 수 있음을 암시하였다. 반죽의 초미세구조를 관찰한 결과 ${\beta}-glucan$ 30% 첨가시 ${\beta}-glucan$ 입자가 반죽에 흡수되지 못하였음을 알 수 있었다. 따라서 제빵적성에 적합한 ${\beta}-glucan$ 첨가율은 20% 이하가 바람직한 것으로 보인다.

배추김치 부재료 혼합의 모델화와 품질 (Studies on Modelization of Subingredients of Chinese-Cabbage Kimchi)

  • 장경숙
    • 동아시아식생활학회지
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    • 제4권3호
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    • pp.147-169
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    • 1994
  • This study was conducted to ivestigate the quality of modeled chinese-cabbage Kimchi. The mutual action of sub-ingredients and optimum mixing conditions were examined by analyses of pH, acidity, content of vitamins, carotenes, number of total microorganism, and Lactobacilli, the activities of softening related to enzymes (polygalacturonase and ${\beta}$-galactosidase), and sensory quality during fermentation. The result about the mutual action of red pepler powder and garlic showed that the pH was decresed as concentration of garlic was higher and that of red peppler powder became lower. Kimchi had unpleasant taste and undesirable odor when the adding ratio of the peper powder and garlic was unbalanced. As the concentration of garlic became higher, the content of vitamin C in Kimchi tissue decreased while that of vitamin C in Kimchi juice increased. The contents of vitamin B1, B2 and carotene increased as the concentration of garlic became lower. The optimum mixing ratio of red pepper powder and garlic evaluated by overall eating quality was 4.66% and 3.45%, respectively. The result about the mutual action of ginger and green onion was that pH became higher as the concentration of ginger was 1.84% and that of green onion was 5.96%. The intensity of fresh taste and odor became stronger as the concentration of ginger increaed to 2.76% and that of green onion decreased to 2.98%. The balance of sour, salty and hot taste became better as the concentration of ginger increased and that of green onion decreased. The optimum mixing condition evaluated by overall eating quality was 2.94% in ginger + 2.78% in green onion. The contents of vitamin B1, B2 and C were high in this condition. The result about the mutual action of leek and salted anchovy juice was that pH became lower as the concentration of leek increased and that of salted anchovy juice decreased. Sour, hot and sweet tastes were good in the condition of leek 12%, salted anchovy juice 4.69%. Palatable, fresh taste and odor became weaker when the one of both sub-ingredients was too much little. The optimum mixing condition evaluated by overall easting quality was 9.76% in leek + 7.32% in salted anchovy juice. The contents of vitamin B1, B2, C and carotene were high in this condition and other sensory qualities were good. The result about the mutual action of salt and sugar was that pH became lower as the concentration of sugar became higher and that of salt became lower. The sweet taste was reduced of hot taste than salty taste. Palatable and fresh tastes were desirable when Kimchi fermented with less salt and more sugar. The optimum mixing condition evaluated by overall eating quality was 3.29% in sugar + 4.80% in salt. The contents of vitamin B1, B1, C and carotene were high in this condition. The result of model Kimchi fermented at 20$^{\circ}C$ was that the number of Lactobacilli in model Kimchi was higher than that of in control Kimchi. The fermentation period was extended under pH 4.0 and the contents of vitamin B1, B1,C and carotene were high through the whole edible period. The activity of polygalacturonase was low, but that of ${\beta}$-galactosidase was high during fermentation.

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Effect of Dietary Genetically Modified ${\beta}$-Carotene Biofortified Rice on Immune in Rats

  • Park, Soo-Jin;Jeong, Mi-Hye;Park, Kyung-Hun;Park, Jae-Eup
    • Reproductive and Developmental Biology
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    • 제36권2호
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    • pp.133-139
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    • 2012
  • This study aims to examine the effect of Genetically Modified ${\beta}$-Carotene Biofortified Rice rice developed by simultaneous expression technology in NAAS on biological immunity. Accordingly, this study added Genetically Modified ${\beta}$-Carotene Biofortified Rice 25, 50% and general rice 50% as control group into diet and provided rats with the prescribed feeds and then measured the contents of immunoglobulin and cytokine in blood. As a result, male and female IgM, IgE, male IgG1, female IgG2a and TNF-a, IL5 and IL12 showed no significant difference; male IgG2a tended to decrease dependently on the combined concentration of Genetically Modified ${\beta}$-Carotene Biofortified Rice; female IgG1 showed significance with control group, but its association with diet was not found. The higher the dietary mixing ratio, the more the male and female IFN-a and female IL-4 contents, regardless of rice variety, and it was found that female IL6 content decreased significantly, but its association with diet was not found. The risk of beta carotene-enriched rice into environment and human body has not been reported yet. The digestion of Genetically Modified ${\beta}$-Carotene Biofortified Rice can be seen as "safe" as this test result showed no big difference between general rice and Genetically Modified ${\beta}$-Carotene Biofortified Rice, and its usability is full of suggestions.

잔골재율 변화에 따른 콘크리트 건조수축 모델링에 관한 연구 (A Study on Modelling for Prediction of Concrete Drying Shrinkage according to Aggregate Ratio of Concrete)

  • 박도경;윤여완;김광서
    • 한국건축시공학회지
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    • 제4권4호
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    • pp.71-77
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    • 2004
  • Drying Shrinkage has much complexity as it has relations with both internal elements of concrete and external factors. Therefore, experiments on Concrete Drying Shrinkage are carried out in this study under simplified circumstances applying temperature & Humidity test chamber which enables constant temperature and humidity. Comparative analyses have been made respectively according to the consequences aiming at modelling for prediction of Concrete Drying Shrinkage and making out measures to reduce it. Strain Rate of Drying Shrinkage of concrete under the condition of dry air appears to rise by about 20%-30% in proportion as the temperature rises $5^{\circ}C$ when the humidity was held below 10% compared under the condition of dry temperature & Humidity test chamber. Strain Rate of Drying Shrinkage in pit sand concrete increased 20% higher than measured when in river sand under the condition of 90-day material age. A general formula with two variables is derived as follow ${\varepsilon}={\alpha}_1+{\beta}_1x_1+{\beta}_2x_2+{\beta}_3x_1^2+{\beta}_5x_2^2$. and also graphed in 3 dimensions, enabling to apply to actual design and predict Strain Rate of Drying Shrinkage in concrete. The results of prediction of Rate of Drying Shrinkage by Response Surface Analysis are as follows. The coefficient of correlation of Drying Shrinkage in Concrete was over 90%.

과립형 β-삼인산칼슘을 사용한 Brushite계 골시멘트의 보관 조건에 따른 경화 특성 (Effect of Storage Conditions on the Setting Properties of Brushite Bone Cement Containing Granular β-Tricalcium Phosphate)

  • 이선애;정태주;오경식
    • 한국세라믹학회지
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    • 제45권10호
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    • pp.625-630
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    • 2008
  • In the bone cement composed of dense granules of $\beta-Ca_3(PO_4){_2}(\beta-TCP)$ and $Ca(H_2PO_4){_2}H_2O$, the compressive strength, setting time and temperature rise were measured to observe the degradation of cement with respect to the stored days before setting. Decreases of compressive strength and temperature rise were observed, while setting time increased with respect to the stored days. The similar trends were repeated with the increase of temperature of storage. Such a change virtually meant the fading of the character of cement and it took place only when the two starting materials were mixed during storage. The degradation could be mitigated taking advantage of granular $\beta$-TCP instead of powdery one. The formation of $CaHPO_4$, which resulted from reaction with ambient humidity, was attributed to the degradation observed during storage. Dependence of the degradation behavior on mixing and temperature during storage was discussed in terms of the driving force for reaction of cement.

Use of Wet Chemical Method to Prepare β Tri-Calcium Phosphates having Macro- and Nano-crystallites for Artificial Bone

  • Chang, Myung Chul
    • 한국세라믹학회지
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    • 제53권6호
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    • pp.670-675
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    • 2016
  • Calcium phosphate crystallites were prepared by wet chemical method for use in artificial bone. In order to obtain ${\beta}$-tricalcium phosphate (TCP), nano-crystalline calcium phosphate (CaP) was precipitated at $37^{\circ}C$ and at $pH5.0{\pm}0.1$ under stirring using highly active $Ca(OH)_2$ in DI water and an aqueous solution of $H_3PO_4$. The precipitated nano-crystalline CaP solution was kept at $90^{\circ}C$ for the growth of CaP crystallites. Through the growing process of CaP crystallites, we were able to obtain various sizes of rectangular CaP crystallites according to the crystal growing times. Dry nano-crystalline CaP powders at $37^{\circ}C$ were mixed with dry macro-crystalline CaP crystallites and the shaped mixture sample was fired at $1150^{\circ}C$ to make a ${\beta}-TCP$ block. Several tens of nm powders were uniformly coated on the surface, which was comprised of powders of several tens of ${\mu}m$, using a vibrator. The mixing ratio between the nanometer powders and the micrometer powders greatly affected the mechanical strength of the mixture block; the most appropriate ratio of these two materials was 50 wt% to 50 wt%. The sintered block showed improved mechanical strength, which was caused by the solid state interaction between the nano-crystalline ${\beta}-TCP$ and the macro-crystalline ${\beta}-TCP$.

Effect of 50 ㎛ class granules on the Injection Behavior of Brushite Bone Cement Prepared via Pre-dissolution Route

  • Mun, Da Hye;Lee, Sang Cheon;Oh, Kyung-Sik
    • 한국분말재료학회지
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    • 제27권6호
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    • pp.468-476
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    • 2020
  • The bone cement used for vertebroplasty must be sufficiently injectable. The introduction of granules reduces the amount of liquid required for liquefaction, implying that higher fluidity is achieved with the same amount of liquid. By employing β-tricalcium phosphate granules with an average diameter of 50 ㎛, changes in injectability are observed based on the paste preparation route and granular fraction. To obtain acceptable injectability, phase separation must be suppressed during injection, and sufficient capillary pressure to combine powder and liquid must work evenly throughout the paste. To achieve this, the granules should be evenly distributed. Reduced injection rates are observed for dry mixing and excessive granular content, owing to phase separation. All these correspond to conditions under which the clustered granules weakened the capillary pressure. The injected ratio of the paste formed by wet mixing displayed an inverted U-type shift with the granular fraction. The mixture of granules and powder resulted in an increase in the solid volume fraction, and a decrease in the liquid limit. This resulted in the enhancement of the liquidity, owing to the added liquid. It is inferred that the addition of granules improves the injectability, provided that the capillary pressure in the paste is maintained.