• 대한전기학회:학술대회논문집
• /
• 대한전기학회 2002년도 추계학술대회 논문집 전기물성,응용부문
• /
• pp.16-18
• /
• 2002

We attempted to fabricate a dendrimer Langmuir-Blodgett(LB) films containing 48 pyridinepropanol functional end group. As the pyridinepropanol functional group could form a complex structure with metal ions. In this study the samples for electrical measurement were fabricated to two types metal complexes with $Pt^{4+}$ and $Fe^{2+}$ ions by LB method. And we have investigated the surface activity at the air-water interface as well as the electrical properties for the monolayers of pure G4-48PyP dendrimer and its complex with metal ions($Pt^{4+}$ and $Fe^{2+}$ ions). In the surface pressure-area($\pi-A$) isotherms of the dendrimers, the stable condensed films formed at the air-water interface and the metal ions effect showed the difference on molecular behavior. We have studied the electrical properties of the ultra thin dendrimer LB films investigated by the current-voltage(I-V) characteristics of metal/dendrimer LB films/metal(MIM) structure. In conclusion, it is demonstrated that the metal ion around G4-48PyP dendrimer can contribute to make formation of network structure among dendrimers and it result from the change of electrical properties.

• 상하수도학회지
• /
• 제18권5호
• /
• pp.573-579
• /
• 2004

Electroflotation, which is used as an alternative to sedimentation, is a separation treatment process that uses small bubbles to remove low-density particulates. Making allowances for recent collision efficiency diagram based on trajectory analysis, it is necessary to tailor zeta potential of bubbles that collide with negatively charged particles. In this paper, the study was performed to investigate the effects of magnesium and aluminium ions on zeta potential of bubbles. And, it was studied to find out factors which could affect the positively charged bubbles. Consequently, zeta potential of bubbles increased both with higher concentration of metal ions and in the acidic pH value. And, a probable principle that explained the procedure of charge reversal could be a combined mechanism with both specific adsorption of hydroxylated species and laying down of hydroxide precipitate. It also depended on the metal ion concentration in the solution to display its capacity to control the bubble surface.

• 한국식품영양학회지
• /
• 제11권5호
• /
• pp.521-527
• /
• 1998

Removabilities of heavy metals(Cd and Pb) by the tea materials (barley-tea, corn-tea, jasmin-tea, brown rice-green tea, black-tea, cassia tora-tea, persimmon peel-tea, and rice-tea) in the tea-water were studied in the various conditions ; particle size of tea (20, 40, 70 mesh), concentration of heavy metal (25, 50, 100 ppm) and extraction temperature(20, 30, 50, 100$^{\circ}C$). The removabilities by the tea solids were increased as the particle size decreased, concentration of heavy metal increased, and extracting temperature increased. Of the nine kinds of tea, Cd and Pb removability by jasmin-tea was highest. In addition, heavy metal removability by cassia tora tea was better than that of other tea as extraction temperature was increased.

• Bulletin of the Korean Chemical Society
• /
• 제4권2호
• /
• pp.76-79
• /
• 1983

The elution behaviors of a series of metal complexes, such as $Co(gly)_{3}$, $[Ni(en)_{3}]^{2+}$, $[Ni(phen)_3]^{2+}$, $[Fe(phen)_3]^{2+}$, $[Co(phen)_3]^3+$, $[Co(tn)_3]^3+$, $[Co(en)_3]^3+$ and $[Co(NH_3)_6]^3+$ (where gly; glycine, phen; phenanthroline, tn; trimethylenediamine, en; ethylenediamine), were studied in aqueous solution by measuring the retention volumes (v values) on SP-Sephadex C-25, cation exchange resin. It was found that the elution behaviors of metal complexes were apparently affected by salt concentrations, kinds of cations in eluent and kinds of anions in eluent, and according to the degrees of their effects coulombic forces, ion exchange capacities, the 'solvent effect' of resin backbone, hydrophobicity and hydrophilicity were applied to explain the elution mechanism.

• Bulletin of the Korean Chemical Society
• /
• 제10권6호
• /
• pp.585-591
• /
• 1989

The effects of the charged metal on the overall electrostatic potential profiles and the capacitances of the electrical double layer are brought out. A model with a simplified jellium and a point-charged electrolyte is utilized in the present calculations. Electrons are assumed not to penetrate electrode surface due to a strong screening of electrolyte at the interface. Electron density functions and ion density functions are obtained, which are also based upon the Poisson equation and Boltzmann equation on either side of the interface. A complete potential profile starting from bulk electrode and ending at bulk electrolyte is obtained by connecting the two potential profiles (one inside the metal electrode, the other inside the electrolyte) with proper boundary conditions. In spite of the simplicity of the model, the present model reveals the importance of the effect of the charged metal on the electrostatic potential profile and the electrical double layer capacitances. The results are discussed and compared with the predictions by Gouy Chapman theory.

• Bulletin of the Korean Chemical Society
• /
• 제25권10호
• /
• pp.1484-1488
• /
• 2004

The thiocyanate-selective PVC membrane electrodes based on 5,10,15,20-tetrakis(2,4,6-trimethylphenyl)-porphyrinatomanganese(III) chloride [Mn(TMP)Cl] and 5,10,15,20-tetrakis(2,6-dichlorophenyl)porphyrinatomanganese(III) chloride $[Mn(Cl_8TPP)Cl]$ as ion carriers were investigated. The effect of ionophores, membrane compositions, plasticizers, and solution pHs on the response characteristics were studied. The Mn(TMP)Cl as an ionophore shows the best potentiometric sensitivity with a slope of -58.7 mV/decade and a detection limit of $log[SCN^-]$ = -6.90, and selectivity for thiocyanate over strong hydrophobic interfering anions such as ${ClO_4}^-$ and salicylate. The potentiometric response is affected by the electronic effect of the substituents and solution pHs. The presence of substituents with electron donating and more liphophilic characters around the ligated metal center produces an improved response toward $SCN^-$.

• Journal of Applied Biological Chemistry
• /
• 제64권4호
• /
• pp.369-374
• /
• 2021

느타리버섯의 갈반병은 Pseudomonas tolaasii에 의해 생성된 톨라신 및 이의 유사 펩티드 독소에 의해 발생한다. 톨라신 펩티드들은 세포막에 pore를 형성하고 버섯의 자실체 구조를 파괴한다. 적혈구가 파괴되는 용혈은 톨라신의 세포독성에 의해 일어난다. 톨라신의 용혈활성은 Zn²⁺ 및 Ni²⁺과 같은 금속 이온에 의해 저해된다. 가돌리니움 이온을 첨가하였을 때, 톨라신에 의한 용혈작용에서 1 mM 이하의 농도에서는 용혈작용이 증가하고 그 이상의 농도에서는 저해되는 이중 효과가 나타났다. 가돌리니움 이온에 의한 톨라신 활성저해 기작은 다른 양이온들에 의한 저해기작과 다른 것으로 보인다. 가돌리니움 이온은 음전하를 갖는 막지질들에 결합하여 지질막의 측압을 변화시키는 것으로 보고되어, 톨라신 이온통로의 여닫힘에 직접 작용하기 보다는 막 구조의 단단함을 증가시켜 막에 대한 톨라신 이온통로의 안정성을 감소시키는 것으로 보인다.

• 한국전기전자재료학회논문지
• /
• 제31권2호
• /
• pp.74-79
• /
• 2018

In this report, the results of a systematic study on the effects of polycrystalline silicon gate depletion on the reliability characteristics of metal-oxide semiconductor field-effect transistor (MOSFET) devices were discussed. The devices were fabricated using standard complimentary metal-oxide semiconductor (CMOS) processes, wherein phosphorus ion implantation with implant doses varying from $10^{13}$ to $5{\times}10^{15}cm^{-2}$ was performed to dope the polycrystalline silicon gate layer. For implant doses of $10^{14}/cm^2$ or less, the threshold voltage was increased with the formation of a depletion layer in the polycrystalline silicon gate layer. The gate-depletion effect was more pronounced for shorter channel lengths, like the narrow-width effect, which indicated that the gate-depletion effect could be used to solve the short-channel effect. In addition, the hot-carrier effects were significantly reduced for implant doses of $10^{14}/cm^2$ or less, which was attributed to the decreased gate current under the gate-depletion effects.

• 대한화학회지
• /
• 제28권2호
• /
• pp.86-94
• /
• 1984

${\beta}-Ag_3SI$의 단결정을 만들어 막전극으로의 응용을 살펴보았다. 그 결과 할로겐 이온들에 대해 감응함을 알았고, 분리용액법과 혼합용액법으로 할로겐 이온들에 대한 선택계수를 얻어 이론값과 비교검토 하였으며, 전위시간 곡선으로 부터 이 전극이 유리 전극기구에 의해 전도함을 알았고, 넓은 pH 범위에서 전위가 일정한 값을 가짐을 알았다. 한편 분석화학에의 응용을 살펴 본 결과 할로겐이온의 혼합용액에서 좋은 지시전극으로 사용할 수 있음을 알았다

• 한국균학회지
• /
• 제19권4호
• /
• pp.282-284
• /
• 1991

$1,000\;{\mu}g/ml$의 카드늄이 함유된 배지에서 배양된 고도 카드늄 내성 Hansenula anomala B-7의 intact cell은 카드늄이 함유되지 않은 배지에 재배양하면 쉽게 용균된다. 그러나 이 intact cell을 $1,000\;{\mu}g/ml$의 카드늄이 함유된 배지에 배양하면 용균이 일어나지 않을 뿐 아니라 왕성하게 재증식 한다. 더욱이 재배양할시 $Na^+$를 포함한 다른 금속을 배지에 첨가하더라도, 이 intact cell의 용균은 방지 되었다.