• Title, Summary, Keyword: Ionic strength

Search Result 540, Processing Time 0.037 seconds

Effect of Carrier Solutions on Particle Retention in Flow Field-Flow Fractionation

  • 문명희
    • Bulletin of the Korean Chemical Society
    • /
    • v.16 no.7
    • /
    • pp.613-619
    • /
    • 1995
  • The influence of carrier solutions on particle retention was studied by varying surfactants and ionic strength in flow field-flow fractionation. Experiments were made with five different submicron polystyrene latex standards at three different types of surfactants and seven different ionic strengths. Departures in particle retention from the general theory were observed. At low ionic strength, it is shown that migrating sample zone is clearly lifted away from the ideal equilibrium height and that the repulsive interaction dominates between the particle and the channel wall. As ionic strength increases up to a certain level, particle retention becomes closer to the general theory. Further increase in ionic strength is shown to prolong the retention. An optimum regime of ionic strength is also suggested with the proper choice of surfactants.

  • PDF

ATPase Activity and Solubility of Actomyosin Extracted from Muscle of Silky Fowl (오골계에서 추출한 Actomyosin 의 ATPase 활성 및 용해도)

  • 정인철;문윤희
    • Journal of the Korean Society of Food Science and Nutrition
    • /
    • v.23 no.5
    • /
    • pp.827-831
    • /
    • 1994
  • Investigation on the extractability, Mg2+-, Ca2+ , EDTA-ATPase activity and solubility of actomyosin prepared from leg and breast muscle of silky fowol were as follows. The extractability of actomyosin in leg and breast muscle was 779mg/100g and 1, 318mg/100g respectively, breast muscle was higher than leg muscle . Mg2+-ATPase activity of actomyosin was high inionic strength 0.02-0.10 and Mg2+ATPase activity of low ionic strength was higher than high ionic strength not related to the part. Ca2+ ATPase activity was high in ionic strength 0.05-0.13, the activity of leg muscle was higher that breast muscle. And EDTA-ATPase activity showed low in low ionic strength and showed high in high ionic strength, and increased greatly depend ionic strength up to 0.4. The solubility of actomyosin was not different in leg and breast muscle , the solution started in KCI concentration of 0.3M and ended in DCI concentration of 0.4M.

  • PDF

Effects of Water Chemistry on Aggregation and Soil Adsorption of Silver Nanoparticles

  • Bae, Sujin;Hwang, Yu Sik;Lee, Yong-Ju;Lee, Sung-Kyu
    • Environmental health and toxicology
    • /
    • v.28
    • /
    • pp.6.1-6.7
    • /
    • 2013
  • Objectives In this study, we investigated the influence of ionic strength and natural organic matter (NOM) on aggregation and soil adsorption of citrate-coated silver nanoparticles (AgNPs). Methods Time-resolved dynamic light scattering measurements and batch adsorption experiments were used to study their aggregation and soil adsorption behaviors, respectively. Results The aggregation rate of AgNPs increased with increasing ionic strength and decreasing NOM concentration. At higher ionic strength, the AgNPs were unstable, and thus tended to be adsorbed to the soil, while increased NOM concentration hindered soil adsorption. To understand the varying behaviors of AgNPs depending on the environmental factors, particle zeta potentials were also measured as a function of ionic strength and NOM concentration. The magnitude of particle zeta potential became more negative with decreasing ionic strength and increasing NOM concentration. These results imply that the aggregation and soil adsorption behavior of AgNPs were mainly controlled by electrical double-layer repulsion consistent with the Derjaguin-Landau-Verwey-Overbeek theory. Conclusions This study found that the aggregation and soil adsorption behavior of AgNPs are closely associated with environmental factors such as ionic strength and NOM and suggested that assessing the environmental fate and transport of nanoparticles requires a thorough understanding of particle-particle interaction mechanisms.

Drug-Biomacromolecule Interaction VIII

  • Kim, Chong-Kook;Yang, Ji-Sun;Lim, Yun-Su
    • Archives of Pharmacal Research
    • /
    • v.7 no.2
    • /
    • pp.87-93
    • /
    • 1984
  • The effects of ionic strength and pH on the binding of cefazolin to bovine serum albumin (BSA) were studied by UV difference spectrophotometry. As ionic strength at constant pH and temperature increases, the apparent bining constant decreased but the number of binding sites remained almost constant at 2. The constancy of the number of binding sites with increasing the ionic strength suggests that purely electrostatic forces between BSA and drug do not have great importance in the drug binding, even though there is a decrease in the apparent binding constant. Thus, the effect of ionic strength on the interaction between drug and BSA may be explained by the changes in ionic atmosphere of the aggregated BSA molecules and competitive inhibition by phosphate ions. In addition, the higher apparent binding constant at high ionic strength is explained by conformational changes of BSA from its aggregate forms into subunits. The pH effects on the afinity of interactions indicated that the binding affinity of cefazoline is higher in the neutral region than in the alkaline region. An d at high pH value, the number of binding sites decreased from 2 to 1 because of the conformational change of BSA in the alkaline region.

  • PDF

Effect of ionic Salt Strength on the Growth and Photosynthetic Rate of Pepper Plug Seedlings (무기 이온의 농도가 고추 플러그묘의 생육과 광합성에 미치는 영향)

  • Ahn, Chong-Kil;Son, Beung-Gu;Kang, Jum-Soon;Lee, Yong-Jae;Park, In-Soo;Choi, Young-Whan
    • Protected Horticulture and Plant Factory
    • /
    • v.12 no.2
    • /
    • pp.68-71
    • /
    • 2003
  • Experiments were conducted to investigate optimal ionic salt strength in nutrient solution for small plug seedlings of ‘Nokgwang’ and ‘Kwari’ green pepper. Plant height increased with increasing ionic salt strength. total leaf area was 72% greater in ‘Nokgwang’ and 18% greater in ‘Kwari’with 2.0 ionic salt strength than that with 1.0 strength. Dry weight per plant tended to increase at higher ionic salt strengths in ‘Kwari’, but to decrease in ‘Nokgwang’ Chlorophyll content increased with increasing ionic salt strength in both cultivars. Photosynthetic rate, stomatal conductance, and transpiration rate were higher for plants fertilized with 1.5 strength than other strengths in both cultivars. Photosynthetic rate peaked at 8.74 $\mu$mol$.$m$^{-2}$ s$^{-1}$ in ‘Nokgwang’ and 5.70 $\mu$mol$.$m$^{-2}$ s$^{-1}$ in‘Kwari’with 1.5 ionic salt strength.

Effect of ionic Strength of Nutrient Solution on Growth and Yield in Cucumber(Cucumis sativus L.) (양액이온 농도 차이가 오이의 생육과 수량에 미치는 영향)

  • 권병선;정현희;신동영;김학진;임준택;현규환;신정식
    • Korean Journal of Plant Resources
    • /
    • v.16 no.3
    • /
    • pp.223-229
    • /
    • 2003
  • This study was carried out to investigate the optimum ionic strength of nutrient solution were treated with a quarter, a half, three quarters, standard, one and half, and double ionic strength of balanced nutrient solution of Yamazaki solution recommended for cucumber plants. Plant height and number of loaves of growing period were rapidly increased in 1/2 ionic strength of nutrient solution. Growth characteristics of cucumber plant as affected by the different ionic strength of nutrient solution were not significant differences, however, in the growing period, plant height, stem length and leaf area were highest in 1/2 ionic strength of nutrient solution. Fruit yield of cucumber plant as affected by the different ionic strength of nutrient solution was not significant differences, however, fruit yield was highest in 1/2 ionic strength of the lowering ionic strength of nutrient solution. Nitrogen concentration was not significant differences, however, it was high corcentration in 1/2 ionic strength of nutrient solution. Growth and yield characteristic of cucumber as affected by 1/2 ionic strength of nutrient solution at 36 days transplanting analyzed correlation cofficient. Plant height showed positive correlated with number of plant and positive correlated with yield.

Electronic Detection of Biomarkers by Si Field-Effect Transistor from Undiluted Sample Solutions with High Ionic Strengths

  • Ah, Chil-Seong;Kim, An-Soon;Kim, Wan-Joong;Park, Chan-Woo;Ahn, Chang-Geun;Yang, Jong-Heon;Baek, In-Bok;Kim, Tae-Youb;Sung, Gun-Yong
    • Bulletin of the Korean Chemical Society
    • /
    • v.31 no.6
    • /
    • pp.1561-1567
    • /
    • 2010
  • In this study, we have developed a new detection method using Si field effect transistor (FET)-type biosensors, which enables the direct monitoring of antigen-antibody binding within very high-ionic-strength solutions such as 1$\times$PBS and human serum. In the new method, as no additional dilution or desalting processes are required, the FET-type biosensors can be more suitable for ultrasensitive and real-time analysis of raw sample solutions. The new detection scheme is based on the observation that the strength of antigen-antibody-specific binding is significantly influenced by the ionic strength of the reaction solutions. For a prostate specific antigen (PSA), in some conditions, the binding reaction between PSA and anti-PSA in a low-ionic strength reaction solution such as 10 ${\mu}M$ phosphate buffer is weak (reversible), while that in high-ionic strength reaction solutions such as 1$\times$PBS or human serum is strong.

Effects of Ionic strength and Anion species on Heavy Metal Adsorption by Zeolite (Ionic Strength 및 공존(共存) 음(陰)Ion이 Zeolite에 의(依)한 중금속(重金屬)의 흡착(吸着)에 미치는 영향(影響))

  • Lee, Jyung-Jae;Park, Byoung-Yoon;Choi, Jyung
    • Korean Journal of Environmental Agriculture
    • /
    • v.7 no.2
    • /
    • pp.96-101
    • /
    • 1988
  • It is important to assess the effects of ionic strength and type of anions when studying the adsorption of heavy metals on zeolite because the background salt may complex with heavy metals and compete for adsorption sites. This experiment was carried out to determine the effect of ionic strength and anion species($Cl^-$, $SO^{2-}\;_4$, and $ClO^-\;_4$) on heavy metal adsorption. Heavy metal adsorption by zeolite from solutions in the range of 10 to 50ppm was studied in the presence of NaCl, $Na_2SO_4$ and $NaClO_4$, with different concentrations. The ionic strength ranged from 0.01 to 1.00. Adsorption of heavy metal cations could be described by the Freundlich isotherm equation. Increasing the ionic strength of equilibrium solutions, the amounts of heavy metal adsorbed on the zeolite surfaces decreased in all three of the anion systems. This fact could be attributed to the competition of background salt cation and the decrease in initial activity of heavy metal cations. In the presence of Cl anion, less adsorption resulted than in the presence of $SO_4$ or $ClO_4$ anions of the same ionic strength, indicating the presence of uncharged and negatively charged complexes of heavy metal with Cl ligands.

  • PDF

Drug Diomacromolecule interaction IX

  • Kim, Chong-Kook;Won, Young-Han;Kim, Sang-Nim
    • Archives of Pharmacal Research
    • /
    • v.7 no.2
    • /
    • pp.95-99
    • /
    • 1984
  • Binding of sulfaethidole to bovine serum albumin (BSA) was studied by circular dichroism. The effects of pH and ionic strength on the binding of sulfaethidole to BSA were investigated. It was found that one primary binding site on the BSAM was capable of inducing optical activity in the presence of sulfaethidole. Enhancement of the induced ellipticity of sulfaethidole upon addition to BSA was not much affected by the change of pH and ionic strength. Taking the effects of pH and ionic strength into consideration, it seems that the binding of sulfaethidole to BSA was not much affected by electrostatic and ionic interactions. Therefore, it might be assumed that the binding was mainly due to the hydrophobic interactions. Sulfaethidole seems to be a reasonable CD probe for the study of hydrophobic drug interactions.

  • PDF

Regulation of Electrochemical Oxidation of Glucose by lonic Strength-Controlled Virtual Area of Nanoporous Platinum Electrode

  • Kim, Jong-Won;Park, Se-Jin
    • Journal of the Korean Electrochemical Society
    • /
    • v.10 no.3
    • /
    • pp.203-206
    • /
    • 2007
  • Electrochemical reaction of glucose was regulated by the electrochemically active area of nanoporous platinum, which is controlled by ionic strength. The profile of the oxidation current of glucose vs. ionic strength was identical with that of the electrochemically active area. This result confirms that the nanopores are virtually opened for the electrochemical reaction of glucose when the ionic strength climbs over a specific concentration and implies that the electrochemical reactions on nanoporous electrode surfaces can be controlled by concentration of electrolyte.