• 제목/요약/키워드: Hydration activity

검색결과 111건 처리시간 0.031초

E. M. F.法에 依한 活性度係數의 測定과 Ion水和에 對한 考察 (The Measurements of the Activity Coefficients by E.M.F. Method and A Study of the Hydration)

  • 사공열;황정의
    • 대한화학회지
    • /
    • 제6권2호
    • /
    • pp.113-116
    • /
    • 1962
  • In this study we have measured the activity coefficients of NaCl in solution by E.M.F. method, depending upon MacInnes' equation at 25 dog. The cell (electrodes) is same as MacInnes' except the cock which was designed by ourselves as figure 1.Additionally, we have calculated the hydration number of NaCl from the activity coefficients using Robinson's equation and ionic hydration number according to our new formula $\frac{n_M{^+}+0.8}{n_A{^-}-0.1}=n_{MA}$, which was mentioned our former thesis.We also have calculated the hydration number of some salts from the ionic hydration number using upper formula and have got reasonable series match with other's value.As the results of our studying, we conclude it as follow;1) Liquid junction potential depend only on the bulk concentration of the both solution.2) The formula $\frac{n_M{^+}+0.8}{{n_A{^-}}-0.1}=n_{MA}$ is reasonable one in deducing to ionic hydration number.3) From upper relation, we can calculate the hydration number of unknown salts from it's ionic hydration numbers.

  • PDF

Benzenesulfonyl 유도체들의 구조와 Staphylococcus aureus에 대한 항균력 (Conformation and Antibacterial Activity on Staphylococcus aureus of Some Benzenesulfonyl Analogues)

  • 김보수;이성희;정우태;강영기
    • 약학회지
    • /
    • 제33권6호
    • /
    • pp.350-360
    • /
    • 1989
  • The conformation and activity of the four benzenesulfonyl analogues of 4-aminobenzene-sulfonamide, 4-aminobenzenesulfonic acid, 4-methylbenzenesulfonamide, and 4-methylbenzenesulfonic acid with antibacterial activity on Staphylococcus aureus were studied using an empirical potential function (ECEPP/2) and the hydration shell model. The conformational energies were minimized from the starting conformations which included possible combinations of torsion angles in each molecule. To understand the hydration effect on the conformation of the molecule in aqueous solution, the hydration free energy of each group was calculated and compared each other. The conformational entropies of low-free-energy coformation of benzenesulfonly analogues were computed by a harmonic approximation. From the correlation of lowest-free-energy conformation of each compound and its antibacterial activity, it was found that the hydration of sulfonyl groups and the substituents are the decisive factors to show antibacterial activities.

  • PDF

On the Hydration Numbers and Activity Coefficients of Some Salts Present in Sea Water

  • Sung, Yong Kil;Jhon, Mu Shik
    • 한국해양학회지
    • /
    • 제5권1호
    • /
    • pp.1-5
    • /
    • 1970
  • The hydration numbers of some salts present in sea water have been calculated by a simple model for the equation of the dielectric constant, and the mean activity coefficients from the theoretical formula proposed by Jhon and Eyring. The validity of the theory for the electrolyte solution is tested by evaluating the hydration numbers and the mean activity coefficients of some 1:1, 1:2, 2:1 and 1:3 electrolytes in sea water. The results show good agreement with the observations.

  • PDF

A Solid-state NMR Study of the Kinetics of the Activity of an Antimicrobial Peptide, PG-1 on Lipid Membranes

  • Kim, Chul;Wi, Sungsool
    • Bulletin of the Korean Chemical Society
    • /
    • 제33권2호
    • /
    • pp.426-432
    • /
    • 2012
  • The activity of an antimicrobial peptide, protegrin-1 (PG-1), on lipid membranes was investigated using solidstate NMR and a new sampling method that employed mechanically aligned bilayers between thin glass plates. At 95% hydration and full hydration, the peptide respectively disrupted 25% and 86% of the aligned 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphotidylcholine (POPC) bilayers at a P/L (peptide-to-lipid) ratio of 1/20 under the new experimental conditions. The kinetics of the POPC bilayers disruption appeared to be diffusioncontrolled. The presence of cholesterol at 95% hydration and full hydration reduced the peptide disruption of the aligned POPC bilayers to less than 10% and 35%, respectively. A comparison of the equilibrium states of heterogeneously and homogeneously mixed peptides and lipids demonstrated the importance of peptide binding to the biomembrane for whole membrane disruption.

혼화재를 사용한 콘크리트의 수화모델 (A Hydration Model for Blended Concrete utilizing Secondary Cementitious Powders)

  • 노재명;변근주;송하원
    • 한국콘크리트학회:학술대회논문집
    • /
    • 한국콘크리트학회 2004년도 춘계 학술발표회 제16권1호
    • /
    • pp.140-143
    • /
    • 2004
  • Heat of hydration of concrete under different curing temperatures can be characterized with knowledge of the thermal activity, the heat rate at the reference temperature, and the total heat of hydration of the mixture. The so-called multi-component hydration model incorporates the effect of following variables: cement chemical composition, cement fineness, secondary cementitious powders, mixture proportions, and concrete properties. However, the model does not consider the use of silica fume as a secondary cementitious powder. Therefore, the model that quantifies the heat of hydration due to the use of silica fume is needed. In this thesis, the effects of silica fume on heat of hydration are evaluated and the influence on the heat of hydration are also quantified to be included in the model, so that the analysis using modified multi-component hydration model for silica fume concrete provides more accurate results than normal concrete.

  • PDF

진한 전해질 용액 중에서 염의 수화수와 활성도 계수에 관한 이론적 연구 (Theoretical Calculation of Hydration Number and Activity Coefficients of Salts in Concentrated Electrolyte Solutions)

  • 성용길;전무식
    • 대한화학회지
    • /
    • 제14권2호
    • /
    • pp.185-192
    • /
    • 1970
  • The extension of the theory of the electrolyte solution to the calculation of the hydration number and the mean activity coefficient of some 1:1 electrolytes in the concentrated solutions has been made. In this derivation, the hydration number has been calculated from the equation of the dielectric constant proposed by Hobbs, Jhon, and Eyring, and the mean activity coefficient from the theoretical formula developed by Jhon and Eyring. The agreement between theory and experiment over a.wide concentration range is quite satisfactory.

  • PDF

MgCO3와 사문석을 사용한 마그네시아 시멘트의 특성평가 (Evaluation of Magnesia Cement Using MgCO3 and Serpentine)

  • 이종규;소정섭;추용식;송훈;박지선
    • 한국재료학회지
    • /
    • 제22권11호
    • /
    • pp.598-603
    • /
    • 2012
  • MgO based cement for the low-temperature calcination of magnesite required less energy and emitted less $CO_2$ than the manufacturing of Portland cements. Furthermore, adding reactive MgO to Portland-pozzolan cement can improve their performance and also increase their capacity to absorb atmospheric $CO_2$. In this study, the basic research for magnesia cement using $MgCO_3$ and magnesium silicate ore (serpentine) as starting materials was carried out. In order to increase the hydration activity, $MgCO_3$ and serpentinite were fired at a temperature higher than $600^{\circ}C$. In the case of $MgCO_3$ as starting material, hydration activity was highest at $700^{\circ}C$ firing temperature; this $MgCO_3$ was completely transformed to MgO after firing. After the hydration reaction with water, MgO was totally transformed to $Mg(OH)_2$ as hydration product. In the case of using only $MgCO_3$, compressive strength was 35 $kgf/cm^2$ after 28 days. The addition of silica fume and $Mg(OH)_2$ led to an enhancements of the compressive strength to 55 $kgf/cm^2$ and 50 $kgf/cm^2$, respectively. Serpentine led to an up to 20% increase in the compressive strength; however, addition of this material beyond 20% led to a decrease of the compressive strength. When we added $MgCl_2$, the compressive strength tends to increase.

순환골재 용출수를 활용한 고로슬래그 미분말 혼입 모르터의 강도특성 (A Study on the Hydration Property of Mortar with Balst Furnace Slag using Water Eluted from Recycled Coarse Aggregates)

  • 신상엽;정의창;김영수
    • 한국건축시공학회:학술대회논문집
    • /
    • 한국건축시공학회 2012년도 추계 학술논문 발표대회
    • /
    • pp.81-82
    • /
    • 2012
  • The purpose of this study is the hydration properties of motar using Blast-Furnace Slag(BFS) with water elured from recycled coarse aggregate. The results of the experiment show that the water eluted from recycled coarse aggregate mixed with blast furnace slag has comparatively higher hydration activity than the mortar not mixed with one in early-age mortar causing the calcium hydroxide in the recycled coarse aggregate to work on as a stimulus to the hydration of ground granulated blast furnace slag. BFS mixed with the eluting water the hydration reaction was a promotion.

  • PDF

박테리아 영양소 성분이 시멘트 복합체의 초기 특성에 미치는 영향 (Effects of Bacterial Nutrients on Early Cement Composites Properties)

  • 장인동;김백중;이종구
    • 대한건축학회논문집:구조계
    • /
    • 제34권3호
    • /
    • pp.53-59
    • /
    • 2018
  • When manufacturing self-healing concrete using bacteria, nutrients are added to increase the activity of the bacteria. Although many researches have focused on the effects of nutrients containing bacterial healing agent on concrete, few have studied the effects of sole nutrient on self-healing of cement composites. Bacterial nutrients, like commercial chemical admixtures, affect hydration characteristics such as flow, setting, hydration heat, mechanical strength of cement composites and also affect the self healing of cement composites by hydration of unhydrated particles. In this study, effect of the four nutrient commonly used in the existing literature on the hydration characteristics of cement composites by its addition was investigated. Flow, setting time, hydration heat, compressive strength have studied for each nutrients added by 1.5% and 3% of cement weight. Experimental results shows that urea and calcium-nitrate can be used up to 3% without significant detrimental effect on cement composites. Addition of calcium-lactate up to 1.5% show better compressive strength than control, but addition of 3% show almost non-hydration. Yeast extract shows detrimental effects on the composites regardless of the amount added.

항균성 펩타이드인 magainin 2의 활성에 대한 고체 핵자기 공명 분광 연구 (A solid-state NMR study on the activity of an antimicrobial peptide, magainin 2)

  • 김철
    • 분석과학
    • /
    • 제24권6호
    • /
    • pp.460-466
    • /
    • 2011
  • 얇은 유리판 위에 정렬된 지질 이중막에 작용하는 항균성 펩타이드 magainin 2의 작용활성을 고체 핵자기 공명 분광법을 이용하여 조사하였다. 수화에 따른 지질 이중막의 파괴정도를 파악하기 위해 두 가지 수화 상태에서 실험이 이루어졌다. 95%의 상대 습도에서 수화된 지질 이중막에서는 약 15% 정도의 지질 이중막이 파괴되었으며, 완전히 수화된 지질 이중막에서는 약 20% 정도의 지질 이중막이 파괴되었다. 두 가지 시료 제조방법에 따른 지질 이중막 파괴 정도의 비교를 통해, 항균성 펩타이드의 지질 이중막 결합과정이 지질 이중막 파괴에 중요한 변수임을 알 수 있었다.