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Behavior of Cadmium, Zinc, and Copper in soils -I. Effect of Organic Matter Treatment on Adsorption of Cadmium, Zinc, and Copper in soils- (토양내(土壤內) 카드뮴, 아연(亞鉛) 및 구리의 행동(行動)에 관한 연구(硏究) -제2보(第-報). 토양내(土壤內) 카드뮴, 아연(亞鉛) 및 구리의 흡착(吸着)에 미치는 유기물처리(有機物處理)의 영향(影響)-)

  • Yoo, Sun-Ho;Hyun, Hae-Nam
    • Applied Biological Chemistry
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    • v.28 no.2
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    • pp.68-75
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    • 1985
  • Laboratory experiments were conducted to investigate the effect of compost and humic acid treatment on adsorption of Cd, Zn, and Cu in soils. Three soils differing in physical and chemical properties used in this experiments were Bonyrang (Typic Udifluvents) SL, Gangseo (Aquatic Eutrochrepts) L, and Gyorae (Typic Distrandepts) SiL. Adsorption of Cd, Zn, ana Cu on the soils followed Langmuir isotherm up to 75 ppm of initial concentration. The adsorption maxima of Cd, Zn, and Cu for the Bonryang soil, the lowest in pH, organic matter content, and CEC, were the lowest of the three soils. Although the Gyorae soil derived from volcanic ash was the highest in organic matter content and CEC, the adsorption maxima of heavy metals for the Gyorae soil were lower than those for the Gangseo soil of which organic content and CEC were intermidiate. The adsorption maxima/CEC ratios for the Bonryang, the Gangseo, the Gyorae soils were found to be in the range of $23{\sim}27%,\;28{\sim}57%$, and $11{\sim}14%$ respectively The bonding energy constants of Cd, Zn, and Cu for the soils were in the order of Gangseo>Bonryang>Gyorae soils. The adsorption maxima of Cd, Zu, and Cu for the Bonryang soil increased with compost treatment by $100{\sim}210%,\;90{\sim}230%$, and $130{\sim}290%$ respectively, while little difference was observed when the soil was treated with humic acid Bonding energy constants of Cd, Zn, and Cu for the Bonryang soil increased significantly with compost treatment, and showed insignificant correlation with humic acid treatment.

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THE CHANGE OF THE CONFIGURATION OF HYDROXYAPATITE CRYSTALS IN ENAMEL BY CHANGES OF PH AND DEGREE OF SATURATION OF LACTIC ACID BUFFER SOLUTION (유산 완충용액의 pH 및 포화도 변화에 따른 법랑질 내 수산화인회석 결정 형태의 변화)

  • Chon, Young-Eui;Jung, Il-Young;Roh, Bung-Duk;Lee, Chan-Young
    • Restorative Dentistry and Endodontics
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    • v.32 no.6
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    • pp.498-513
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    • 2007
  • Since it was reported that incipient enamel caries can be recovered, previous studies have quantitatively evaluated that enamel artificial caries have been, remineralized with fluoride showing simultaneously the increase of width of surface layer and the decrease of width of the body of legion. There is, however, little report which showed that remineralization could occur without fluoride. In addition, the observations on the change of hydroxyapatite crystals also have been scarcely seen. In this study, enamel caries in intact premolars or molars was induced by using lactic acidulated buffering solutions over 2 days. Then decalcified specimens were remineralized by seven groups of solutions using different degree of saturation(0.212, 0.239, 0.301, 0.355) and different pH(5.0, 5.5, 6.0) over 10 days. A qualitative comparison to changes of hydroxyapatite crystals after fracturing teeth was made under SEM(scanning electron microscopy) and AFM(atomic force microscopy). The results were as follows: 1. The size of hydroxyapatite crystals in demineralized area was smaller than the normal ones. While the space among crystals was expanded, it was observed that crystals are arranged irregularly. 2. In remineralized enamel area, the enlarged crystals with various shape were observed when the crystals were fused and new small crystals in intercrystalline spaces were deposited. 3. Group 3 and 4 with higher degree of saturation at same pH showed the formation of large clusters by aggregation of small crystals from the surface layer to the lesion body than group 1 and 2 with relatively low degree of saturation at same pH did. Especially group 4 showed complete remineralization to the body of lesions. Group 5 and 6 with lower pH at similar degree of saturation showed remineralization to the body of lesions while group 7 didn't show it. Unlike in Group 3 and 4, Group 5 and 6 showed that each particle was densely distributed with clear appearance rather than crystals form clusters together.

반응표면분석에 의한 쇠고기 야채 쌀죽의 이화학적 및 관능적 특성 변화

  • 이용욱;금준석;은종방
    • Proceedings of the Korean Society of Postharvest Science and Technology of Agricultural Products Conference
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    • 2003.10a
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    • pp.167.2-168
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    • 2003
  • 현대 사회는 서구적인 식생활의 변화로 인해 조리가 간편하고 조리 시간이 짧은 즉석식품과 영양 기호식품을 동시에 충족시켜주는 음식에 대한 소비가 늘고 있는 실정이다. 또한 최근 미곡의 공급량에 비해서 소비량이 해마다 감소하여 재고미의 증가를 볼 때, 쌀의 새로운 이용방법 모색이 절실히 요망된다. 따라서 쌀의 소비촉진과 현대사회의 소비형태를 접목시켜서 쇠고기와 야채를 이용한 즉석쌀죽을 개발하고자 하였다. 쇠고기, 야채 및 쌀가루를 이용한 soup mix의 최적 배합비를 설정하기 위하여 제조조건에 따라 다르게 제조한 쇠고기 야채 쌀죽의 이화학적 및 관능적 특성에 미치는 변화를 조사하였다. 이때 야채의 배합비에 따른 이화학적 및 관능적 특성을 모니터링 하고자 반응표면분석법 (response surface methodology, RSM)을 이용하였다. 요인변수(Xn)를 쌀의 양에 대한 버섯의 비율 (X$_1$), 당근의 비율 (X$_2$), 대파의 비율 (X$_3$)로 하여 중심합성계획에 따라 17실험구로 구분하여 조리실험을 실시하였고, 반응변수(Yn)는 soup mix를 이용하여 제조한 쇠고기 야채 쌀죽의 이화학적 특성인 색도의 L*값 (Y$_1$), a*값 (Y$_2$), b*값 (Y$_3$), 점도(Y$_4$), 퍼짐성 (Y$_{5}$), 고형분 함량(Y$_{6}$), PH (Y$_{7}$)으로 하였으며 관능적 특성인 색 (Y$_{8}$), 향 (Y$_{9}$), 점성 (Y$_{10}$), 맛 (Y$_{11}$), 전체적인 기호도 (Y$_{12}$)를 종속변수로 하여 회귀분석에 이용하였다. 회귀분석에 의한 모델식의 예측에는 SAS (statistical analysis system)program을 사용하였으며, 3차원 반응표면 분석법으로 해석하였다. 야채의 배합비에 따라 제조한 쇠고기 야채 쌀죽의 물리적 특성인 색도의 L*, a*, b* 값에 대한 반응표면 회귀식의 $R^2$은 각각 0.6098(p> 0.05), 0.8803 (p <0.05), 0.6781(p> 0.05)로서 b값에 있어서 그 유의성이 5%수준에서 인정되어 b값에 미치는 영향이 크다는 것을 알 수 있었다. L*값은 63-68사이로, a*값은 0.13에서 -0.89사이를 b*값은 2-5값 사이에서 변화하여 제조한 죽의 색이 옅은 황색임을 알 수 있었다. 고형분 함량, 퍼짐성과 pH에 대한 $R^2$은 각각 0.4280, 0.5433과 0.2406임을 볼 때 버섯, 당근, 대파의 비율에 따라 제조한 쇠고기 야채 쌀죽의 고형분 함량, 퍼짐성과 pH는 설정된 범위내에서 그 유의성이 인정되지 않아 큰 영향을 미치지 않음을 알 수 있었다. 관능검사 결과, 색과 향에 대한 반응표면 회귀식의 $R^2$은 각각0.6000과 0.7825이고 P-value는 각각 0.4290과 0.0942로서 5% 수준에서 유의한 상관성이 없음을 확인할 수 있었다. 맛과 점성에 대한 $R^2$은 0.8717과 0.8068이고 P-value는 각각 0.0195 (p <0.05)와 0.0612로서 야채의 배합비에 따라 맛에 있어서 유의확률 5%수준에서 그 유의성이 인정되었으며, 전체적인 기호도에 대한 유의성은 $R^2$이 0.8463이고 P-value는 0.0344 (p <0.05)임을 볼 때, 설정된 범위내에서 야채의 배합비에 따라 제조한 쇠고기 야채 쌀죽의 맛과 기호도에 큰 영향을 미치는 것을 알 수 있었다. 그리고 최대 임계점이 버섯의 첨가량은 0.99%, 당근의 첨가량은 0.97%, 대파의 첨가량은 0.59%에서 최적 반응표면을 나타내었다. 이상의 결과로 볼 때, 야채의 배합비에 따른 맛과 전체적인 기호도에 있어서 그 유의성이 5%수준에서 모두 유의한 상관관계를 보였으며, soup mix 제조시 쌀가루 양에 대한 야채의 최적 배합비는 버섯, 당근, 대파에 있어서 각각 0.99, 0.97과 0.59%임을 알 수 있었다.

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Some Properties of the Polyphenol Oxidase from Potatoes (Solanum tubersum L.) and Inhibiting Effect of the Polyphenol Oxidase by Sulfites (감자 Polyphenol Oxidase의 효소학적 성질 및 아황산염에 의한 활성억제 효과)

  • Ha, Young-Duk;Lee, Mi-Ock
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.17 no.3
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    • pp.198-204
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    • 1988
  • This study was aimed at obtaining elementary data on enzymatic browning of potato and potato products and examining the inhibitory method of browning. Therefore, we extracted polyphenol oxidase from potatoes(Solanum tubersum L.), and investigates its general properties and inhibiting effects of its activity with the different concentrations of sulfites($Na_2S_2O_4,\;Na_2SO_3{\cdot}7H_2O,\;NaHSO_3$). The optimum pH and temperature of polyphenol oxidase were observed to be 6.5 and $37^{\circ}C$ respectively. The polyphenol oxidase at PH5 was very stable, and the activity of polyphenol oxidase between pH $5.0{\sim}9.0$ was estimated to be relatively high, showing $72{\sim}75%$ of its activity at pH5. The polyphenol oxidase was very stable when heated at $40^{\circ}C$ for one hour, and almost 50% of enzyme activity was decreased when heated at $70^{\circ}C$ for twelve minutes. At 0.1mM concentrating of sulfites the relative activity of polyphenol oxidase was 98% in all the three cases of sulfites. Thus sulfites at 0.1mM concentration was found to have little inhibiting effect on polyphenol oxidase activity. At 1mM concentration of sulfites $NaHSO_3$ showed the lowest 36% relative activity among the three. At 5mM concentration of sulfites, the relative activity of $Na_2SO_3{\cdot}7H_2O$ was the lowest 14%.

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Numerical Approach for Evaluation of Forest Soil Fertility (수치적(數値的) 접근방법(接近方法)에 의(依)한 산림토양(山林土壤)의 비옥도(肥沃度) 평가(評價))

  • Ma, Sang Kyu
    • Journal of Korean Society of Forest Science
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    • v.35 no.1
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    • pp.1-8
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    • 1977
  • Forest soil fertility was evaluated through the approach of numerical method. In this study, the soil chemical properties analyzed for 35 different soil series as table 2 were cited in numerical analysis. Minimum contents of essential nutrients in the surface soil for a satisfactory growth of tree in the plantation were evaluated by comparing with Wild's standard as table 1. Demanding level of fertilization were evaluated by using the formula 1 as table 5. Similar relation of soil chemical properties between soil series were calculated through formula 2, and then classified into 5 groups in soil chemical properties. 1. General chemical properties of surface soil in case of 35 soil series. About 40 percent of 35 different soil series are less than 2 percent in organic matter, 10 ppm in available phosphorus, 1.25m.e/l00g in exchangeable calcium and 0.5m.e/l00g in exchangeable magnesium. Generally, shortage of exchangeable potash are not found. CEC less than 10m.e/l00g are in two thirds and strong acid soil less than PH 5.5 are in about four fifths. 2. Soil series requested or not the fertilization are indirectly evaluated from the formula 1 using the relative figure of chemical components of CEC, OM and MgO. Through this analysis, 8 different soil series have very poor quality in soil chemical capacity so that demands highly the fertilization. On the other hand, other 13 different soil series group have not been thought to need the fertilization according to chemical guality. 3. By the results comparing the similarity of chemical properties of forest soil, it is thought to be suitable that the forest soil fertility are divided into 5 groups as follows: 1. Low CEC soil 1-1 Low organic matter soil less than 2 percent 1-2 Medium organic matter soil less than 4 percent 2. High CEC and organic matter soil 2-1 Low magnesium soil 2-2 High magnesium soil 3. High magnesium and calcium soil as lime stone.

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Synthesis and Electrochemical Properties of (La0.6Sr0.4)(Co0.2Fe0.8)O3 cathode for SOFC on pH Control Using Modified Oxalate Method (Modified Oxalate Method 의해 합성한 SOFC용(La0.6Sr0.4)(Co0.2Fe0.8)O3 Cathode의 pH 변화에 따른 특성)

  • Lee, Mi-Jai;Choi, Byung-Hyun;Kim, Sei-Ki;Park, Sang-Sun;Lee, Kyung-Hee
    • Journal of the Korean Electrochemical Society
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    • v.10 no.4
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    • pp.288-294
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    • 2007
  • The LSCF cathode far Solid Oxide Fuel Cell was investigated to develop high performance unit cell at intermediate temperature by modified oxalate method with different electrolytes and different pH. The LSCF powders employed La, Sr, Co and Fe oxides, oxalic acid, ethanol and $NH_4OH$ solution were synthesized with pH controlled as 2, 6, 7, 8, 9 and 10 at $80^{\circ}C$ Single crystalline phase was obtained from pH $2{\sim}9$. on the other hand, $La_2O_3$ appeared from pH 10. Very fine powder with particle size of 50 nm was obtained at calcination temperature of $800^{\circ}C$ for 4 hours. LSCF cathode synthesized at pH 7 showed the highest electric conductivity in the temperature range of $600^{\circ}C$ to $900^{\circ}C$ its value was 950 S/cm at $900^{\circ}C$ Under same synthesis conditions, polarization resistance of each LSCF cathode was changed with different calcination temperatures. As-prepared powder presented 2.52, 1.54 and $2.58\;{\Omega}$ at $600^{\circ}C$ with ScSZ, 8Y-YSZ and GDC as its electrolyte respectively after calcination at $800^{\circ}C$ for 4 hours.

The Key Success Factors of University Entrepreneurship Education: Implication from USA University Cases (대학 창업교육 핵심 성공요인: 미국 대학 사례의 시사점)

  • Choi, Jong-In;Park, Chygwan
    • Asia-Pacific Journal of Business Venturing and Entrepreneurship
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    • v.8 no.3
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    • pp.85-96
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    • 2013
  • Entrepreneurship courses and programs in Korean universities tend to increase steadily but seem to have some limitations. They are usually recognized as another domain of Business Administration. Entrepreneurship program is practical like Business Administration but should be much more interdisciplinary than that. Because Korean Entrepreneurship programs are in the early stage, they must be reinforced with factors such as education culture, faculties, curriculum and relationships with communities. This study aims to get some implications from Entrepreneurship programs have been run by universities in America in order to facilitate Entrepreneurship program in Korean universities. Based on 11 success factors found by our case universities' Entrepreneurship programs and Kauffman Campus, this study has drawn implications of critical success factors of Entrepreneurship programs as follow. First of all, because Entrepreneurship programs should focus on Entrepreneurship mind sets such as innovative idea generation and courage to overcome risk, it is more desirable that Entrepreneurship programs are introduced in all departments of universities such as Arts, Science and Engineering. These programs also need to take interdisciplinary approach and required to be opened from liberal arts course. In order to be sustained during all their academic careers, vision, mission and strategy for Entrepreneurship programs should be based on strong leadership and support of top leaders. Entrepreneurship culture of each university is also one of the most important success factors. Entrepreneurship programs not only as major programs but also as specific Entrepreneurship minors designed for departments such as Arts, Science and Engineering could be considered according to each university's situation. This study also suggest to make a motivation system for Entrepreneurship faculties, Ph d. programs for Entrepreneurship, communication network for Entrepreneurship programs and mentor system in community. To begin Entrepreneurship programs, it also needs to develop good education contents as many as possible. When it concerned with teaching method, project based 4 year program can be suggested to be effective and efficient. To introduce project based program that should be consistent till participants' graduation, university must prepare regulations to support team teaching, mentor and interdisciplinary cooperation. To dissipate the concept that Entrepreneurship is another version of management, this study support the idea that Entrepreneurship programs should be designed and run by independent and central-focused governance system, Entrepreneurship education center.

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Effect of Aqueous Phase Composition on the Stability of a Silica-stabilized Water-in-oil Emulsion (유화제로서 실리카를 이용한 유중수형 에멀젼의 안정성에 미치는 수상부 조성의 영향)

  • Kim Jin-Hwang;Kim Song-I;Kyong Kee-Yeol;Lee Eun-Joo;Yoon Moung-Seok
    • Journal of the Society of Cosmetic Scientists of Korea
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    • v.30 no.3 s.47
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    • pp.353-359
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    • 2004
  • The extent of silica flocculation can be modified by varying the silica concentration, aqueous phase pH, salt and polvmer concentration. High volume fraction W/O emulsion stabilized by hydrophobic silica was established with various aqueous phase conditions for cosmetic application. By increasing the silica concentration up to $1.0\;wt\%,$ the size of droplet decreased. A high silica concentration increased the viscosity of continuous oil phase by network formation, which resulted in target size of droplet. The stability of W/O emulsion is improved as increasing the aqueous phase pH. At low and intermediate pH, the emulsions became more stable by adding salt $(0.083\;mol\;dm^{-3}\;MgSO_4).$ At high PH, the presence of salt caused significant destabilization. The gelation behavior of the emulsion indicates that the effect of salt on silica-stabilized emulsion is derived from an electrostatic attraction. The addition of xanthan gum in aqueous phase increased the mono-dispersity of the W/O emulsion by making water more hydrophobic and hindering the recombination of droplets. In conclusion, these results indicate that very stable emulsifier-free, finely dispersed W/O emulsion can be achieved for cosmetic application by changing the aqueous phase composition.

Intermacromolecular Complex Formation between Helix Strilctilral Polypeptides through Hydrogen Bonding (수소 결합을 통한 Helix 폴리 펩타이드사이의 복합체 형성)

  • 조병기;김창규
    • Journal of the Society of Cosmetic Scientists of Korea
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    • v.18 no.1
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    • pp.99-132
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    • 1992
  • Polypeptide has been used broadly as an active ingredient in cosmetics We thought it is very important to investigate the adsorption behavior of polypeptide in order to pre-estimate the effect of these polypeptides. For the study of polypeptide adsorption, we have investigated complex formation of basic homopolypeptides, poly(L-proline) Form I [PLP(I)], Form II [PLP(II)] and poly(4-hydroxy-L-proline) (PHLP) with acidic homopolypeptides, poly(L-glutamic acid) (PLGA), poly(D-glutamic acid) (PDGA) and poly(L-aspartic acid) (PLAA) through hydrogen bonding in a hydroalcoholic medium with viscometer, 1ight scatter, pH meter and circular dicroism (CD). The polypeptides used in this study have helical structure in some conditions. The result exhibited that al 1 the complexes were formed as the composition of basic/acidic homopolypeptide : L:2 irrespective of the complex systems used. A more favorable complex is formed in the PLP(II)-PLGA system than PHLP-PLGA because PLP(II) has a more flexible helical conformation, whereas PHLP has a more rigid helical conformation. The right-handed helix PLGA formed the complex favorably and quickly with the left-handed helix PLP(II), whereas the left-handed helix PDGA formed the complex favorably with the right-handed helix PLP(I). The effect of side chain of the acidic homopolypeptides on the complexation was also studied. The result showed that more favorable condition for the complexation was PLGA-PLP(II) system which has longer side chain at acidic homopolypeptide than PLAA - PLP(II). All the above facts were well supported by CD measurement for the complex systems. By the CD spectra for the complexes we could deduce the conformational change of each homopolypeptide in the complexes On the basis of the above results, we performed the adsorption test of PLP(I, II) and PHLP on the hair having a left-handed helix. The adsorption amount of each polypeptide was analyzed by HPLC. The result showed that PLP(I) was adsorbed more than PLP(II), PLP(II) was adsorbed more than PHLP on the hair. On adsorbing polypeptides having a helical structure on the hair through hydrogen bonding, it could be concluded that the helical polypeptides having the opposite directional structure to the hair are adsorbed more than those having the same directional structure with the hair and also the polypeptides having a flexible conformation are adsorbed more than those having a rigid conformation.

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Endogenous Phenoloxidase Purified from an Earthworm, Lumbricus rubellus (붉은 지렁이(Lumbricus rubellus) 체내로부터 정제한 Phenoloxidase)

  • 백승렬;조은정;유경희;김유삼;서정진;장정순
    • The Korean Journal of Zoology
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    • v.39 no.1
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    • pp.36-46
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    • 1996
  • An endogenous phenoloxidase (EPO) from earthworm, Lumbricus rubellus, has been purified and characterized. The purified EPO using ammonium sulfate fractionation, Blue-2, Phenyl-, and Q-sepharose chromatography steps was revealed in SDS-PAGE as a single protein banri with Mr. of 59 kl)a. A native strudure of the enzyme was examined with an in situ staining of a nondenatudng-PAGE using DL-dopa as a substrate. The result showed that a single band due to the EPO activity was located siighdy above a standard polypeptide with Mr. of 210 kl)a. These fads indicate that the EPO is an oligomeric enzyme. The presence of a monophenolase activity of the purified EPO, which hydroxylates tyrosine to dopa, was confirmed by observing dopachrome accumulation at 475 nm at PH 8.0 with a typical lag phase during 60 mm. of meausrement. A series of inhibition study has been performed for the enzyme with several divalent cation chelators such as phenyithiourea (Flu), 1, lO-phenanthroline, EDTA, and EGTA. Among them, only V'flj inhibited the enzyme with 1C0.5 of 65 MM, which indicated that copper was critical for the catalysis of EPO. The enzyme was maximally active at 35'C and pH 8.0 when L-dopa to dopachrome conversion was spectrophotometricaily monitored at 475 nm. The apparent Km values of P0 for L-opa were obtained as 1.86 mM and 13.8 mM at pH 6.5 and 8.0, respectively. The catalytic efficiencies at both pH were almost identical [(kat/Km)pH8.0/(kcat/Km)pH6.5 = O.92] while the Vmax at p11 8.0 was 6.6-fold higher than that at pH 6.5. This fact may indicate that pH affeds the catalysis at substrate and/or enzyme-substrate complex level rather than the enzyme itself. Taken together, the EPO was an oligomeric enzyme which did not require proteolysis for its activation. These results also indicated that the enzyme can exist, at least, in part as a latent form In vivo, which might be distinct from the prophenoloxidase activating system. Therefore, it is pertinent to consider that there must be certain regulatory molecules or phenomena in L. rubellus which make the 1,0 in a latent form in vivo before the foreign invasions.

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