• Title/Summary/Keyword: charge interaction

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Two-dimensional Supramolecular Structures by Hydrogen and Halogen Interactions

  • Yoon, Jong-Keon;Kim, Ho-Won;Chung, Kyung-Hoon;Kahng, Se-Jong
    • Proceedings of the Korean Vacuum Society Conference
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    • 2010.02a
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    • pp.354-354
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    • 2010
  • Supramolecualr ordering has been actively studied due to it's possible applications to the fabrication processes of nano-electronic devices. Van der Waals interaction and hydrogen bonding are frequently studied mechanisms for various molecular structures based on non-uniform charge distributions. Halogen atoms in molecules can have electrostatic interactions with similar strength. Big halogen atoms have strong non-uniform charge distributions. To study molecular orderings formed by hydrogen and halogen interactions, we chose a molecular system containing oxygen, hydrogen, and bromine atoms, a bromo-quinone. A two-dimensional molecular network was studied on Au(111) using a low-temperature scanning tunneling microscope. Bromo-quinone molecules form self-assembled square grids having windmill structures. Their molecular orderings, chiral structures, and defects are explained in terms of hydrogen and halogen interactions.

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Photophysical Behaviors of Biphenylcarboxylic Acids in Various Solvents; Excited-State Geometry Change and Intramolecular Charge Transfer

  • Yoon Minjoong;Cho Dae Won;Lee Jae Young
    • Bulletin of the Korean Chemical Society
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    • v.13 no.6
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    • pp.613-620
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    • 1992
  • The solvent-dependent photophysical properties of 2-biphenylcarboxylic acid (2BPCA) and 4-biphenylcarboxylic acid(4BPCA), which have a pre-twisted conformation in the ground state, have been investigated. The fluorescence spectra of 4BPCA show vibrational structure with a non-mirror image to the absorption spectra in nonpolar solvent while those of 2BPCA show no structure even in nonpolar solvents. As the solvent polarity increases, the fluorescence spectra become diffuse and broad with a strong red shift resulting in the large Stokes shift. The large fluorescence Stokes shift of BPCA's in polar solvent is also partially due to an intramolecular charge transfer (ICT) interaction in the excited state, as demonstrated by the large dipole moment in the excited state (7.6-10.6 D). The fluorescence decay behaviors of BPCA's (decay-times and their pre-exponential factors) also depend on solvent polarity in agreement with the solvent-dependent properties of the steady-state fluorecence. The data have been discussed in terms of change in the excited-state potential energy surface with respect to change of the dihedral angle of biphenyl moiety.

A Study on the changes of electric charge induced by Apchim (押鍼) manipulation during acupuncture therapy (자침시(刺鍼時) 압침(押鍼)의 수기자극(手技刺戟)이 전위변화(電位變化)에 미치는 영향(影響))

  • Song, Moon-Young;Shim, Won-Bo;Kim, Young-Tae;Baek, Dae-Bong;Ahn, Sung-Hun;Kim, Kyoung-Sik;Sohn, In-Cheul
    • Korean Journal of Acupuncture
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    • v.22 no.4
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    • pp.9-27
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    • 2005
  • Objective : hypothesis. First of all, there exists electric property in meridian and meridian point. Second of all, energy flowing in meridian is related with electric property. Third of all, there is electronic interaction between the operator who performs acupuncture therapy and the receiver who is given acupuncture therapy. Forth of all, acupuncture effects may depend on the electric capacity which is transferred between the operator and the receiver via acupuncture needle. Methods : Under the hypothesis, I studied the effects of electric charge in ST37(+) and ST39(-) generated by Apchim (押鍼) manipulation which was stimulated at ST36 point. And compared with data on the changes of electric charge from the hand of the operator during acupuncture stimulation. Electric charge induced via acupuncture needle from the operator may be important factor that causes the changes of electric charge in meridian and acupoint in the receiver. Therefore we investigated the changes of electric charge induced by the operator using Maclab 400 by the following methods. The one was in stable electric circle condition and the other was in unstable electric circle condition. In this experiments, the changes of electric charge from the stimulation type of Apchim manipulation performed in our lab condition in acupuncture therapy was induced at least three factor, one was the difference of bio-potentials between the operator and the receiver of acupuncture therapy, another was the depth of acupuncture insertion from the skin of the receiver the other was an electromyogram of the receiver. Results :The data imply that the first factor should make a capacitance current when the operator touched the acupuncture needle which was inserted in the receiver. Therefore, the results suggest that capacitance currents stimulus in electronic view may be important factor in acupuncture therapy between the operator and the receiver of acupuncture therapy.

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A Study on Skill Upgrading and Job Satisfaction in Hotel Cooks (호텔조리사의 직무 만족과 숙련 향상에 관한 연구)

  • Park, Kyung-Kon
    • Culinary science and hospitality research
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    • v.11 no.4 s.27
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    • pp.59-76
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    • 2005
  • The purpose of this study is to illuminate the influence happened by the process of acquirement of professional cooking skills related to satisfaction with duty of hotel cooks according to the development and expansion of the food service industry. First, interaction with colleagues, working environment, accomplishment of duty, satisfaction of duty etc. have a big effect on improvement of cooking skills, that is, acquirement and accumulation of cooking skill. Therefore, it's confirmed that improvement of skill can be promoted if we focus on this kind of factors and meet more positively. Second, field education training should be operated professionally with systematic education training. Third, duty rotation has an effect on skill advancement. It can be interpreted that oppressive feelings caused by ability, skill, knowledge, human relations etc. which is required in new business related to frequent change of the business in one's charge can have an effect on duty satisfaction. It's considered that comprehensive and in-depth study should be accomplished in future concerning duty rotation, field training.

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Interactions of Membrane and PMAP-23 Studied by $^{31}P$ solid-state NMR Spectroscopy

  • Kim, Si-Won;Kim, Suhk-Mann
    • Journal of the Korean Magnetic Resonance Society
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    • v.11 no.2
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    • pp.110-114
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    • 2007
  • [ $^{31}P$ ] powder pattern spectra were measured to investigate the aspects of the interaction between the MLV (Multilamellar vesicle) and PMAP-23, a membrane of cathelicidin family and then CSAs(chemical shift anisotropy) were calculated to indentify the extent of perturbation of phospholipid mobility by the peptides. We found that acidic phospholipid interacts strongly with PMAP-23, and the analogues which modified to increase the amphipathic property showed that larger change of CSA. The analogue which introduced positive charge showed the same effects with amphipathic property.

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A Study About Necessity of a Teacher Center for Elementary and Middle School Teachers (초.중등교사를 위한 교사 센터 설립에 관한 연구)

  • Chang, Won-Hie
    • Journal of the Korean Institute of Educational Facilities
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    • v.5 no.4
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    • pp.18-27
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    • 1998
  • Our gorvernment announced an educational reformation bill to establish the institutional foundation of educational system on May 31, in 1995. To secure the open education which is to foster students' creativity, individualization and personalization, it was requested that the past teacher-centered system should be changed to learner-centered system. To gurantee such a change, however, there are many conditions that has to be satisfied first. I think that the most important thing for the new system is a close interaction between teachers and students. To accomplish a successful interaction, the teachers' understanding and attitude toward their students must change at first. The purpose of this study is to examine what kind of understanding and attitude the teachers need, and what kind of roles teachers must take charge of. At the same time, I suggest that we need to establish a Teacher Center to give teachers a seperate place to learn new theories, and to exchange among themselves the informations they got from the actual field experience.

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Interaction of Oxygen and Chlorine Dioxide in Pulp Bleaching (I) -Studies on the Degradation of Lignin Model Compounds- (펄프 표백시 산소와 이산화염소의 상호작용 (제1보) - 리그닌 모델화합물 연구 -)

  • 윤병호;황병호;김세종;최경화
    • Journal of Korea Technical Association of The Pulp and Paper Industry
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    • v.35 no.3
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    • pp.74-78
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    • 2003
  • The structural property of phenolic and non-phenolic lignin has an effect on the reaction rate of lignin by oxygen and chlorine dioxide respectively. Moreover, the undesirable degradation of cellulose followed by lignin degradation is influenced by chemical charge and reaction time. In this paper, several lignin model compounds were used to illuminate the interaction of oxygen and chlorine dioxide by varying the position of O and D(OD, DO, ODO and DOD), and gas chromatography method was used to investigate the degradation of lignin by determining the content of methoxyl groups in lignin. It was shown that structural properties of lignin models were more influential on the degradation and demethylation of lignin than the above combination. Combination of oxygen and chlorine dioxide, however, was more effective in degradation of lignin than only one stage, and three stages than two stages.

Solvent Effect on the Dynamics of Radical Ion Pair Separation

  • Han, Chul-Hee
    • Journal of Photoscience
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    • v.8 no.1
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    • pp.33-37
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    • 2001
  • Picosecond absorption spectroscopy has been employed in the study of the solvent dynamics of 1, 2, 4, 5-tetracyanobenzene/biphenyl derivative radical ion pairs, and the resulting rates of radical ion pair separation are faster in acetonitrile than in dichloromethane. In an effort to account quantitatively for such solvent effect on the rate of radical ion pair separation, an equation for the rate of radical ion pair separation is introduced, in which the rate depends exponentially on the electrostatic interaction energy in the radical ion pair. In our analysis of the types of electrostatic interaction energy based on the conducting spheres in dielectric continuum was chosen, and the rate equation employing this electrostatic energy provided information on the distance on the distance of radical ion pair separation and solvation energy of the radical ion pair, thereby providing quantitative explanation for the observed solvent effect on the rate of radical ion pair sepaaration.

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Inelastic two-degree-of-freedom model for roof frame under airblast loading

  • Park, Jong Yil;Krauthammer, Theodor
    • Structural Engineering and Mechanics
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    • v.32 no.2
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    • pp.321-335
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    • 2009
  • When a roof frame is subjected to the airblast loading, the conventional way to analyze the damage of the frame or design the frame is to use single degree of freedom (SDOF) model. Although a roof frame consists of beams and girders, a typical SDOF analysis can be conducted only separately for each component. Thus, the rigid body motion of beams by deflections of supporting girders can not be easily considered. Neglecting the beam-girder interaction in the SDOF analysis may cause serious inaccuracies in the response values in both Pressure-Impulse curve (P-I) and Charge Weight-Standoff Diagrams (CWSD). In this paper, an inelastic two degrees of freedom (TDOF) model is developed, based on force equilibrium equations, to consider beam-girder interaction, and to assess if the modified SDOF analysis can be a reasonable design approach.

Anion Photoelectron Spectroscopy and Theoretical Calculation of the Hetero-dimers of Polycyclic Aromatic Hydrocarbons

  • Kim, Namdoo;Lee, Sang Hak
    • Bulletin of the Korean Chemical Society
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    • v.34 no.5
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    • pp.1441-1444
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    • 2013
  • Hetero-dimer anions of naphthalene (Np), anthracene (An), phenanthrene (Ph) and pyrene (Py) were investigated using the time-of-flight mass spectrometer (TOF-MS), anion photoelectron spectroscopy (PES) and theoretical calculation. There are two possible geometries with their electron affinity (EA) difference: parallel displaced (PD) and T-shaped. Dispersion force plays a key role in PD structure with the formation of a new anionic core while ${\pi}$-hydrogen interaction plays a key role in T-shaped structure with the monomer anionic core. The optimized structures and charge distributions can simply be explained by the relative difference of EA.