• Title/Summary/Keyword: charge interaction

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Spectrophotometric Determination of Antihistaminics by using Iodine as Electron Acceptor (요오드를 전자수용체로 한 항히스타민제의 분광학적 분석)

  • Moon, Hong-Seob;Baik, Chai-Sun
    • YAKHAK HOEJI
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    • v.33 no.3
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    • pp.141-148
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    • 1989
  • The weak UV absorbing antihistaminics such as chlorpheniramine, triprolidine, tripelennamine and diphenhydramine were analyzed by charge-transfer spectrophotometric method. The results obtained are summarized as folows. It was possible to determine a weak UV absorbing antihistaminics using the intense charge-transfer UV bands in chloroform. Charge transfer complexes were formed in a 1:1 ratio between antihistaminics and iodine in chloroform. Linear relationship was found between absorbance and concentration in the range of $1.0\;{\times}\;10^{-5}M-5.0\;{\times}\;10^{-5}M$ for chlorpheniramine( ${\varepsilon}\;=\;2.082\;{\times}\;10^4$) and tripelennamine ( ${\varepsilon}\;=\;1.578\;{\times}\;10^4$), $1.0\;{\times}\;10^{-5}M-8.0\;{\times}\;10^{-5}M$ for triprolidine ( ${\varepsilon}\;=\;1.120\;{\times}\;10^4$) and $1.0\;{\times}\;10^{-5}M-1.0\;{\times}\;10^{-4}M$ for diphenhydramine ( ${\varepsilon}\;=\;9.900\;{\times}\;10^3$). Charge transfer complexes of chlorpheniramine, triprolidine and tripelennamine have absorption maxima at 293 nm and complex form of diphenhydramine has absorption maximum at 270 nm. By UV, IR spectra, it could be inferred that CT-complexes were formed by interaction between the basic nitrogen of antihistaminics as electron donor (non bonding electron) and iodine as electron acceptor (${\sigma}$ bonding electron).

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A new opinion about the electrical peculiarity of meridian and acupoint (경혈 및 경락의 전기적 특성에 관한 또 다른 이해)

  • Ahn, Seong-Hun
    • Korean Journal of Acupuncture
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    • v.25 no.2
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    • pp.33-41
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    • 2008
  • Objectives : The aim of this study was to understand electro-physiological peculiarity in meridian and acupoints, and understand acupuncture therapy mechanism as an electro-physiological viewpoints. Methods : I reviewed the articles on the electro-physiological peculiarity of the meridian and acupoints Results and Conclusions : It has been reported that meridian and acupoints have high-electrical conductivity and row-electrical resistance. On this scientific basis, to understand the mechanism of acupuncture therapy, I made some hypotheses. At first, there is electro-property in meridian and acupoint. The second, energy flowing in meridian is related with electro-property. The third, there is electronic interaction between practitioner of acupuncture therapy and patient receiving acupuncture therapy. The forth, acupuncture effects which may be expressed by the electro-charge capacity is transfered between practitioner and patient via acupuncture. Electro-charge induced via acupuncture in practitioner may be an important factor that initiate the electro-charge changes in meridian and acupoint of patient.

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Collapse of Charge Ordering in Ru-doped Mono-layered Manganites

  • Hong, Chang-Seop;Kim, Wan-Seop;Hur, Nam-Hwi
    • Journal of Magnetics
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    • v.8 no.2
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    • pp.85-88
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    • 2003
  • The magnetic and transport properties far single crystals of Ru-doped mono-layered manganites $La_{0.5}Sr_{1.5}-Mn_{1-x}Ru_xO_4$ (0$\leq$$\chi$$\leq$0.1) have been studied using neutron diffraction and magnetization measurements. Temperature dependent magnetization data reveal that with an increase in the Ru concentration the parent charge ordered antiferromagnetic state is gradually destroyed and new ferromagnetic phase evolves. In the low Ru-doped system spin glass behavior is apparent in low temperature region, which is confirmed by ac and do magnetization measurements. The competing magnetic interaction between Mn/Mn and Mn/Ru couples is the most likely cause of the spin glass transition.

Self-consistent electronic structure of impurities using the recursion method

  • Park, Jin-Ho;Cho, Hwa-Suck;Lee, Gun-Woo
    • Journal of Korean Vacuum Science & Technology
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    • v.2 no.1
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    • pp.13-19
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    • 1998
  • We have calculated the electronic structure of impurity atoms in metal host by using the tight binding model in the recursion method. For a self-consistent calculation, we assumed that the effect of impurity introduction was localized only at the impurity site and its neighbours. We calculated the Madelung term by limiting the contribution to Vm of the charge perturbations to the first shell around the impurity with Evjen technique. The calculated local density of states and charge transfer values have been compared with the experimental values for a single impurity in metal host. We fund that d-reso-nance state came from the repulsive interaction between impurity d-state and host band, and the position of d-resonance state depended on the difference of valence electrons between the host and the impurity. the results also showed that the charge transfer value between an impurity and host metal was comparable to the ionicity difference between them.

Role of London Energy in Determining the C-Dimensions of Phyllosilicates (층상 규산염광물 C-축 결정에 있어서의 런던에너지 역할)

  • 유재영
    • Journal of the Mineralogical Society of Korea
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    • v.3 no.2
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    • pp.89-97
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    • 1990
  • To examine how London energy controls the c-dimensions of phyllosilicates, London energy, as well as Coulomb and Pauli repulstion energy was calculated as a function of d(001) for 1M and d(002) for 2M 1 phyllosilicates. London and Pauli repulstion energy calcualtion use a direct interaction calculation method and Coulomb energy calculation adopts Fourier synthesis method. The energy calculations show that Coulmb and Pauli repulsion energy dominantly control the c-dimensions of phyllosilicates having the interlayer cationss, i.e., the layer charges. On the other hand, if phyllosilicates have no interlayer cations, London energy is solely responsible for holding the layers and maintain the c-dimensions. The significance of London energy in determining the c-dimensions of phyllosislicates de-creases as the layer charge increases. When the layer charge is lower than one equivalent on the basis of Oη(OH)2 formula, London energy plays an important role in determing the c-dimensions. however, if the layer charge is higher than one equivalent, London energy becomes insignifi-cant in determining the c-dimension.

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The Moderating Effect of the Physical Environmental-level Between Infant Teachers' Positive Play Beliefs and Teacher-infant Interaction (영아교사의 긍정적 놀이신념이 영아와의 상호작용에 미치는 영향에서 물리적 환경수준의 중재효과)

  • Lee, Mijin;Lee, Wanjung
    • Korean Journal of Childcare and Education
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    • v.15 no.6
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    • pp.41-57
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    • 2019
  • Objective: The purpose of this study was to investigate the moderate effect of the physical environmental-level between infant teachers' positive play beliefs and teacher-infant interaction. Methods: The subjects of this study were 483 teachers in charge of one-year-old and two-year-old infants in child care centers located in metropolitan areas. The data were collected by asking the teachers to respond to a questionnaire and the data collected were analyzed through correlation and hierarchical multi- regression analysis. Results: First, the positive play beliefs of the infant teacher, the physical environment level, and the teacher-infant interaction showed significant proportional correlations. Second, the physical environment level moderated the influence of the teacher's positive play beliefs on teacher-infant interaction. In particular, results showed that functional interior space configuration, outdoor playground composition and facilities among the sub-variables of the physical environment level had a moderating effect. Conclusion/Implications: The results of this study show that teachers with positive play beliefs have positive teacher-infant interaction when there is sufficient space available for infants and teachers. This indicates that the human and physical environments of child care centers can promote teacher-child interaction.

Anomalous Behavior of the Ethyl Group in the Aminolysis of S-Phenyl Acetate with Benzylamine in Acetonitrile

  • Lee, Ik-Choon;Lee, Hai-Whang;Lee, Byung-Choon;Choi, Jin-Heui
    • Bulletin of the Korean Chemical Society
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    • v.23 no.2
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    • pp.201-204
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    • 2002
  • The rates of the aminolysis of S-phenyl substituted-acetate series $(RC(=O)SC_6H_4Z$, with R=Me, Et, i-Pr, t-Bu and Bn) with benzylamines $(XC_6H_4CH_2NH_2)$ are not correlated simply with the Taft's polar $({\sigma}^{\ast})$ and/or steric effect constants $(E_s)$ of the substituents due to abnormally enhanced rate of the substrate with R=Et. Furthermore, the cross-interaction constant, ${\rho}x_z$ , is the largest with R=Et. These anomalous behaviors can only be explained by invoking the vicinal bond $({\sigma})$-antibond $({\sigma}^{\ast})$ charge transfer interaction between C-$C{\alpha}$ and C-S bonds. In the tetrahedral zwitterionic intermediate, $T^{\pm}$ , formed with R=Et the vicinal ${\sigma}_{c-c}-{\sigma}^{\ast}_{c-s}$ delocalization is the strongest with an optimum antiperiplanar arrangement and a narrow energy gap, ${\Delta}{\varepsilon}={\varepsilon}_{{\sigma}^{\ast}}-{\varepsilon}_{\sigma}$. Due to this charge transfer interaction, the stability of the intermediate increases (with the concomitant increase in the equilibrium constant K (= $k_a/k_{-a}$)) and also the leaving ability of the thiophenolate leaving group increases (and hence $k_b$ increases) so that the overall rate, $k_n\;=\;Kk_b$, is strongly enhanced. Theoretical support is provided by the natural bond orbital (NBO) analyses at the B3LYP/6-31+$G^{\ast}$ level. The anomaly exhibited by R=Et attests to the stepwise reaction mechanism in which the leaving group departure is rate limiting.

Optical Probing of Electronic Interaction between Graphene and Hexagonal Boron Nitride (hBN)

  • Ahn, Gwanghyun;Kim, Hye Ri;Ko, Taeg Yeoung;Choi, Kyoungjun;Watanabe, Kenji;Taniguchi, Takashi;Hong, Byung Hee;Ryu, Sunmin
    • Proceedings of the Korean Vacuum Society Conference
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    • 2013.02a
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    • pp.213-213
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    • 2013
  • Even weak van der Waals (vdW) adhesion between two-dimensional solids may perturbtheir various materials properties owing to their low dimensionality. Although the electronic structure of graphene has been predicted to be modified by the vdW interaction with other materials, its optical characterization has not been successful. In this report, we demonstrate that Raman spectroscopy can be utilized to detect a few % decrease in the Fermi velocity ($v_F$) of graphene caused by the vdW interaction with underlying hexagonal boron nitride (hBN). Our study also establishes Raman spectroscopic analysis which enables separation of the effects by the vdW interaction from those by mechanical strain or extra charge carriers. The analysis reveals that spectral features of graphene on hBN are mainly affected by change in vF and mechanical strain, but not by charge doping unlike graphene supported on $SiO_2$ substrates. Graphene on hBN was also found to be less susceptible to thermally induced hole doping.

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The Effects of $Ca^{2+}$on the Interaction of Nonionic Surfactant with Iodine in Aqueous Solution (수용액 중에서 비이온성 계면활성제와 요오드간의 상호작용에 미치는 $Ca^{2+}$의 영향)

  • Kwon Oh-Yun;Paek U-Hyon
    • Journal of the Korean Chemical Society
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    • v.36 no.5
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    • pp.621-626
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    • 1992
  • The effects of $Ca^{2+}$ ion on the charge transfer(CT) interaction of $4-(C_9H_{19})C_6H_4O(CH_2CH_2O)_{40} [NP-(EO)_{40}]$ with iodine in aqueous solution were investigated by UV-visible spectrophotometer. Maximum absorption wavelengths to the CT interaction were in the vicinity of 390 nm, and by the addition of $Ca^{2+}$ ion shifted toward 370 nm. Above CMC, the intensity of the CT interaction by the addition of $Ca^{2+}$ ion were increased and then decreased. The increase in the intensity of CT band were attributed to the increase of the donor-acceptor overlap with iodine caused by the compactness of micelle in the presence of $Ca^{2+}$ ion. These phenomena suggest that the linear oxyethylene(EO) chains, relatively free to assume various configuration in aqueous solution, could form a pseudo-crown ether structures capable of forming complexes with $Ca^{2+}$ ion.

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ANALYSIS OF CHARGE COLLECTION EFFICIENCY FOR A PLANAR CdZnTe DETECTOR

  • Kim, Kyung-O;Kim, Jong-Kyung;Ha, Jang-Ho;Kim, Soon-Young
    • Nuclear Engineering and Technology
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    • v.41 no.5
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    • pp.723-728
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    • 2009
  • The response property of the CZT detector ($5{\times}5{\times}5\;mm^3$), widely used in photon spectroscopy, was evaluated by considering the charge collection efficiency, which depends on the interaction position of incident radiation, A quantitative analysis of the energy spectra obtained from the CZT detector was also performed to investigate the tail effect at the low energy side of the full energy peak. The collection efficiency of electrons and holes to the two electrodes (i.e., cathode and anode) was calculated from the Hecht equation, and radiation transport analysis was performed by two Monte Carlo codes, Geant4 and MCNPX. The radiation source was assumed to be 59.5 keV gamma rays emitted from a $^{241}Am$ source into the cathode surface of this detector, and the detector was assumed to be biased to 500 V between the two electrodes. Through the comparison of the results between the Geant4 calculation considering the charge collection efficiency and the ideal case from MCNPX, an pronounced difference of 4 keV was found in the full energy peak position. The tail effect at the low energy side of the full energy peak was confirmed to be caused by the collection efficiency of electrons and holes. In more detail, it was shown that the tail height caused by the charge collection efficiency went up to 1000 times the pulse height in the same energy bin at the calculation without considering the charge collection efficiency. It is, therefore, apparent that research considering the charge collection efficiency is necessary in order to properly analyze the characteristics of CZT detectors.