• 제목/요약/키워드: pH variation

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Byssochlamys fulva가 생성하는 펙틴질 분해효소에 관한 연구 I (Studies on the Pectolytic Enzymes from Byssochlamys fulva I)

  • 남영중;김남수;홍순우
    • 미생물학회지
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    • 제21권1호
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    • pp.1-6
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    • 1983
  • Effects of carbon sources, incubation time, incubation temperature, initial incubation pH, and vitamin B complex on the polygalacturonase activity of Byssochlamys fulva were studied to confirm the optimum conditions for the production of that enzyme. When pectin was used as carbon source, polygalacturonase activity reached to the maximum value of 0.50 units/ml. After 5 days of incubation, polygalacuturonase activity reached to its maximum of 0.48units/ml. Polygalacturonase activities were similar between $25^{\circ}C\;and\;45^{\circ}C$, however, decreased dramatically in the outside of this range. Polygalacturonase activity was not signicicantly influenced by the variation of initial incubation pH. However, at pH5.0, polygalacturonase activity was slightly through the addition of thiamine and riboflavin, and the optimum concentrations were $10^{-2}M$ in case of thiamine and $10^{-3}M$ in riboflavin.

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전해법에 의한 Mn-ferrite 생성 (The formation of Mn-ferrite by electrolysis)

  • 김유상;황용길
    • 한국표면공학회지
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    • 제25권1호
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    • pp.1-7
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    • 1992
  • The formation of manganese ferrite has been performed to investigate some properties according to the variation of compositions, pH, current density by electrolysis. It has been found that the amount of oxidized weight of anode were increased with increasing current density. The amount of oxidized weight of anode were most in pH 10. As the result of X-ray diffraction Mn Fe₂O₄ crystal composition in pH13. When the particles of Mn/sub x/ Fe/sub 3-x/O₄ were heated at 300℃, it has been shown typical Mn Fe₂O₄(JCPDS Card No. 10-319) in X=1 composition. As the result of SEM observation, the size of MnFe₂O₄ particles were about 0.1㎛, the shape of particles were spherical type. According to the above mentioned experimental condition, 0.1-0.5㎛ sub-micron particles of manganese ferrite were formed from the wasted manganese dry cell, through washing → reduction → electrloysis.

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팔프 및 제지공장 폐수의 처리에 관한 미생물학적 연구 1

  • 홍순우;하영칠;강영화
    • 미생물학회지
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    • 제10권1호
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    • pp.9-28
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    • 1972
  • 1. To get the suitable yeasts for the tratment of waste liquor from pulp and paper industries, the 162 yeasts were isolated from the waste liquor, decayed trees and sewage (1, 7, 8, 9, 1971). 17 species were chosen by its ability to assimilate the carbon compounds and indentified. 2. All of the strain was increased its growing ability by agitation. In particular, the strain 912, strain 613, strain 100, strain 732 showed excellent high productive ratio(A/$A_{0}$). 3. The optimum temperature of the strains rangel $27^{\circ}C$ and $30^{\circ}C$. 4. Most of the strain was grown actively in 10C/5N-composition and strain 113, strain 432, strain 735, strain 936, and strain 912 showed its optimum growing in 15C/5N-composition and 5C/5N-composition, respectively. 5. The optimum pH of the strains lay within range pH 4.5-6. Effect of the variation of pH on the growth was nearly negligible within this range. 6. The strain 912, strain 100, strain 613, strain 311, strain 235, and strain 732 were expected for the utilization to the treatment of the waste liquor from pulp and paper industries.

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Diazotized Chitin에 고정된 $\beta$-glucosidase의 생물 반응기에서의 동특성 (Characteristics of $\beta$-glucosidase Immobilized on the Diazotized Chitin in Bioreactors)

  • 김종덕;이경희송승구
    • KSBB Journal
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    • 제6권2호
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    • pp.147-156
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    • 1991
  • Diazotized chitin (CHITN) was synthesized reacting with NaN3 and HCl to alkaline hydrolyzed chitin for the support of immobilized enzyme. Immobilized $\beta$-glucosidase on diazotized chitin(CHITN-Gase) was produced reacting with glutaraldehyds as bifunctional reagent. CHITN-Gase activities were determined reacting with p-nitrophenol-$\beta$-D-glucopyranoside in plug flow reactor as a reference. Optimum temperature, optimum pH, reaction constant and deactivation rate were determined with variation of flow rate and H/D. The particle size of immobilized enzyme in the best was, 35 mesh (CHITN35-Gase). The optimum conditions of immobilized enzyme were $70^{\circ}C$ in temperature and 5.0 in pH. Diameter and flow rate of plug flow reactor in the best was 8.5mm in diameter and 0.8ml/min in flow rate. Reaction constant was mainly influenced by electrostatic force. The best glucose hydrolizing activities of CHITN3 5-Gase was 3.34$\times$10-5 M/1. while that of native-$\beta$-glucosidase was 2.44$\times$10-5 M/1.

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감나무 둥근무늬낙엽병균(Mycosphaerella nawae)의 배양적 특성 (Cultural Characteristics of Mcyosphaerella nawae causing Spotted Leaf Casting of Persimmon)

  • 권진혁;강수웅;정부근;박창석
    • 식물병과 농업
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    • 제1권2호
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    • pp.18-21
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    • 1995
  • Mycosphaerella nawae, the causal organism, of spotted leaf casing disease of persimmon, was isolated from infected leaves showing typical symptom. The cultural characteristics of the fungus were compared on artificial media. Among 24 different combinations of culture media and supplements, oatmeal agar+persimmon leaf extract (PLE) and PAD+ PLE+streptomycin showed the highest rate of isolating as 57.1%. The best medium for mycelial growth of the fungus was PDA+persimmon leaf powder (PLP). The colony diameter was reached 47mm for 30 days at 2$0^{\circ}C$. PDA+PLE also supported good mcyelial growth showing 46mm of diameter in same condition. The optimum growth temperature of this fungus in PDA was recognized fairly low. The mycelial growth was higher at 2$0^{\circ}C$ than 15$^{\circ}C$. The variation of pH between pH 4 to pH 8 did not affect to the mycelial growth of the pathogen.

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염화 제1구리와 제2구리 혼합용액의 이온평형 (Ionic Equilibria in Mixed Solutions of Cuprous and Cupric Chloride)

  • 이만승
    • 대한금속재료학회지
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    • 제46권1호
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    • pp.20-25
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    • 2008
  • The ionic equilibira in mixed solutions of cuprous and cupric chloride were analyzed by considering chemical equilibria, mass and charge balance equations. The activity coefficients of solutes were calculated by using Bromley equation. Required thermodynamic constants and interaction parameters were evaluated from the data reported in the literature. The effect of NaCl and CuCl concentrations on the pH and potential of the mixed solutions was explained in terms of the variation in the concentration of solutes and in the activity of hydrogen ion. The calculated pH values of the mixed solutions agreed well with the measured values. However, the calculated values for the potential of the mixed solutions were lower than the measured values, indicating the necessity of considering the complex formation between cuprous and chloride ion, such as $Cu^2Cl{_4}^{2-}$ and $Cu_3Cl{_6}^{3-}$.

Ex12 helper phage improves the quality of a phage-displayed antibody library by ameliorating the adverse effect of clonal variations

  • Choi, Hyo-Jung;Song, Suk-Yoon;Yoon, Jae-Bong;Liu, Li-Kun;Cho, Jae-Youl;Cha, Sang-Hoon
    • BMB Reports
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    • 제44권4호
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    • pp.244-249
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    • 2011
  • The quality of a phage-displayed antibody library deteriorates with clonal variations, which are caused by differentially expressed Escherichia coli antibody genes. Using the human Fab SP114 against the pyruvate dehydrogenase complex-E2 (PDCE2), we created four E. coli TOP10F' clones with a pCMTG phagemid encoding Fab-pIII (pCMTG-Fab), Fd ($V_H+C_{H1}$)-pIII (pCMTG-Fd), or light chain (L) (pCMTG-L), or the vector only (pCMTG-${\Delta}Fab$) to investigate the effect of clonal variations in a defined manner. Compared to the others, the E. coli clone with pCMTG-Fab was growth retarded in liquid culture, but efficiently produced phage progenies by Ex12 helper phage superinfection. Our results suggest that an antibody library must be cultured for a short duration before helper phage superinfection, and that the Ex12 helper phage helped to alleviate the detrimental effect of clonal variation, at least in part, by preferentially increasing functional phage antibodies during phage amplification.

파푸아뉴기니지역의 지속적 마 재배 방향 (Prospect of Sustainable Organic Yam Production in Lae, Papua New Guinea)

  • 장광진;서규선;안철현;황대선;변재면;박철호;전운성;엘릭
    • 현장농수산연구지
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    • 제14권1호
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    • pp.181-193
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    • 2012
  • 1) LAE지역으로 강우량이 풍부하고 햇볕의 양이 많은 지역으로 토양산도는 마 재배에 이상적인 pH(H2O)가 평균 6.40이다. 그러나 포장에 따라 편차가 심하게 나타나고 있어 재배 기술 보급이 시급한 실정이다. 2) 평균 pH(H2O)는 6.4이지만, pH(KCL)가 3.9로 나타났다. 두 pH 차이가 2.5로 심한 양분부족 현상을 보이고 있다. 토양 EC는 0.18 mS/cm로 심각한 토양 수탈현상을 보이고 있다. 3) 토양의 산화환원전위 (ORP)는 393mV로 아주 이상적인 토양을 보이고 있다. 토양산도와 함께 산화환원전위(ORP)는 좋은 유기농 마를 만드는데 큰 역할을 하고 있다. 4) 마는 연중 양분(養分)을 흡수하고 있는데, 측정 결과는 전 항목에서 심한 양분의 부족현상을 보여 향후 유기물의 투입이 요구되고 있다. 그러나 전반적으로 토양은 심한 양분부족 현상을 보이며 부분적으로 심각한 토양 수탈현상을 보이고 있었다. 토양영양에 대한 조사 연구가 지속가능한 유기농 마를 생산할 수 있는 기반임을 인식하는 계기가 되었다.

Objective and Subjective Quality Characteristics of Pork Longissimus Muscle as a Function of the Ultimate pH

  • Cho, Byung-Wook;Oliveros, Maria Cynthia;Park, Kyoung-Mi;Do, Kyoung-Tag;Lee, Ki-Hwan;Seo, Kang-Seok;Choi, Jae-Gwan;Lee, Moon-Jun;Cho, In-Kyung;Choi, Byoung-Chul;Ryu, Kyeong-Seon;Hwang, In-Ho
    • 한국축산식품학회지
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    • 제29권6호
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    • pp.685-694
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    • 2009
  • The aim of the present study was to evaluate the variation in ultimate pH of commercial populations of pure-breed (Landrace, Duroc and Yorkshire) pig's longissimus muscles and their effect on objective meat quality traits and sensory characteristics. Fifty boars were sampled from 184 pigs, which were reared at three breeding farms and slaughtered at a commercial abattoir. The selection was determined based on ultimate pH, and animals were segregated into three groups: low pH (pH $\leq$ 5.5, n=13), medium pH (pH 5.5 to 5.6, n=18) and high pH (pH $\geq$ 5.6, n=16). The breeds had no significant effects; however, pigs with a higher ultimate pH had significantly (p<0.05) higher intramuscular fat content, lower level of polyunsaturated fatty acids, lower level of lipid oxidation and higher eating quality compared to those with lower ultimate pH. As the ultimate pH increased, the relative proportion of C14:0, C16:0 and C18:1 increased while C18:2n6 and C20:4n6 decreased. The present study demonstrates that the economic value of pigs can be characterized by the ultimate pH and/or intramuscular fat content. However, these results do not necessarily indicate that a high ultimate pH directly corresponds to high intramuscular fat content and vice versa.

자이오머의 산성용액에 대한 산중화능 (Acid Neutralizing Capacity of Giomer in an Acidic Solution)

  • 안하나;김선미;최남기
    • 대한소아치과학회지
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    • 제40권3호
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    • pp.168-176
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    • 2013
  • 본 연구는 자이오머의 산성용액에서 시간에 따른 산중화능을 평가하고, 산에 노출된 자이오머의 표면변화를 관찰하기 위해서 시행되었다. 실험군으로는 수복용 자이오머인 Beautifil II와 유동성 자이오머인 Beautifil Flow F02, 대조군으로 수복용 복합레진인 $Filtek^{TM}$ Z250을 선택하였고, 원판과 가루 형태로 시편을 제작하여 pH 2.0의 염산 수용액과 혼합한 후 pH 값을 측정하였으며, 분말 형태의 자이오머는 새로운 염산 용액과 재혼합 후 pH 값을 측정하였다. 또한 주사전자현미경을 이용하여 원판형태 시편의 표면구조의 변화를 관찰하여 다음과 같은 결과를 얻었다. 원판 형태의 실험에서는 수복용 자이오머만이 실험 24시간 이후 유의한 pH 값의 증가를 보였다. 반면, 분말 형태의 실험에서는 수복용, 유동성 자이오머 모두 초기부터 유의한 수준의 pH 증가가 보였으며, 수복용 자이오머가 더 높은 pH 증가를 보였다. 분말 형태의 자이오머는 새로운 염산용액에서 이전 실험에 비해 낮은 정도의 pH 증가를 보였다. 또한, 충전용 자이오머의 표면에서 레진과 유동성 자이오머에 비해 더 많은 부식성의 구조적 변화가 발생했다. 결론적으로, 자이오머는 산중화능을 가지며, 필러 함량이 높은 충전용 자이오머는 유동성 자이오머보다 더 큰 산중화능이 있음을 알 수 있었다.