• Title/Summary/Keyword: LB method

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Surface Structure and Electrical Properties of Polyurethane LB Monolayers (폴리우레탄 LB단분자막의 표면구조 이미지와 전기적 특성)

  • 서정열;김도균;정상범;유승엽;신훈규;박재철;권영수
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2000.11a
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    • pp.320-323
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    • 2000
  • We attempted to fabricate polyurethane derivatives (PU-CN, PU-DCM) LB films by using LB method. Also, we investigated the monolayer behavior at the air-water interface by surface pressure-area ($\pi$-A) isotherms. And, the surface morphologies and the physicochemical properties of LB films were investigated by atomic force microscopy (AFM) and UV-vis spectroscopy, respectively. Also, the electrical properties of polyurethane derivatives LB films were investigated by using the conductivity and the dielectric constant. In the AFM images, we conclude that surface morphology of PU-DCM LB films is smooth and homogeneous and has optimal hydrophobicity and good stability, whereas PU-CN LB films give rougher surfaces with more excess material. In the I-V characteristics, the conductivity is different as to the polyurethane derivatives, it is considered that this phenomena could be described by the difference of lumophore pendant which was adhered at PU main chain.

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Design of LB-DECK Based on Performance Evaluation (성능 평가에 근거한 LB-DECK의 설계)

  • Cho, Gyu Dae;Lho, Byeong Cheol;Cho, Hyun Chul
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.15 no.4
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    • pp.99-106
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    • 2011
  • This study performed research for improvement on basic concept of PBD applying suitable design method before and after LB-DECK composition. According to study, in this case, before composition, it can reduce minuteness cracks by increasing bending tensile strength utilizing polymer concrete, can expect sensuous effect, improve durability as to low permeability, and was evaluated that can reduce covering depth according as it. Also, because LB-DECK baseplate that apply the empirical design method composite is superior load resistance ability than general baseplate, safety is increased, it is expected to secure constructibility and economic performance at the same time because reinforcement arrangement method and reinforcement amount are fixed even if span effective span is increased at ultimate strength design method application.

A Study on the Mechanism of Opening-with-Pungent/Lowering-with-Bitter Method of Wenbing and the Spleen/Stomach Disease Treatment in Piweilun (온병학(溫病學) 신개고강법(辛開苦降法)과 『비위론(脾胃論)』의 비위병(脾胃病) 치료 기전에 대한 고찰)

  • Ahn, Jinhee;Kim, Do-hoon
    • Journal of Korean Medical classics
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    • v.33 no.3
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    • pp.91-109
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    • 2020
  • Objectives : The aim of this paper is to compare the mechanisms of the OP/LB method and the SSD treatment in 『Piweilun』. Methods : Wenbing texts, articles on the OP/LB method, and the 『Piweilun』 was examined for comparison of treatment mechanisms of SSD. Results : The mechanism of the OP/LB method in treating SSD was to treat the Spleen and Stomach separately, to restore the ascending/descending pattern of qi through simultaneous use of pungent and bitter flavors which raises and lowers, respectively. Moreover, the use of medicinals with contrary properties regulate the other's biased nature, and none of the medicinals create dampness. The pungent and bitter flavors play central roles, where the pungent flavor opens and communicates and the bitter flavor clears and lowers. The treatment method of SSD in the 『Piweilun』 treat the Spleen and Stomach together, with a focus on raising and dispersing through upraising yang and reinforcing qi by means of Wind medicinals with pungent and bitter flavors added to sweet and warm medicinals. Conclusions : Owing to the expansion of the OP/LB method concept by modern-contemporary scholars, the potential for treating SSD as can be seen in the 『Piweilun』 with the OP/LB method has emerged. The similarity between the OP/LB method and treatment of SSD in the 『Piweilun』 is that the objective of the formulas is to lower fire heat and communicate qi to help qi movement. This common objective allows for treatment of SSD within Wenbing and those in 『Piweilun』 with the said formulas through appropriate modification fit for each situation.

In-vitro investigation of the mechanical friction properties of a computer-aided design and computer-aided manufacturing lingual bracket system under diverse tooth displacement condition

  • Kim, Do-Yoon;Ha, Sang-Woon;Cho, Il-Sik;Yang, Il-Hyung;Baek, Seung-Hak
    • The korean journal of orthodontics
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    • v.49 no.2
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    • pp.73-80
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    • 2019
  • Objective: The purpose of this study was to compare the static (SFF) and kinetic frictional forces (KFF) of a computer-aided design and computer-aided manufacturing lingual bracket (CAD/CAM-LB) with those of conventional LB (Con-LB) and Con-LB with narrow bracket width (Con-LB-NBW) under 3 tooth displacement conditions. Methods: The samples were divided into 9 groups according to combinations of 3 LB types (CAD/CAM-LB [Incognito], Con-LB [7th Generation, 7G], and Con-LB-NBW [STb]) with 3 displacement conditions (no displacement [control], maxillary right lateral incisor with 1-mm palatal displacement [MXLI-PD], and maxillary right canine with 1-mm gingival displacement [MXC-GD]; n = 6/group). While drawing a 0.016-inch copper or super-elastic nickel-titanium archwire with 0.5 mm/min for 5 minutes in a chamber maintained at $36.5^{\circ}C$, SFF and KFF were measured. The Kruskal-Wallis method with Bonferroni correction was performed. Results: The Incognito group demonstrated the highest SFF, followed by the 7G and STb groups ([STb-control, STb-MXLI-PD, Stb-MXC-GD] < [7G-MXC-GD, 7G-MXLI-PD, 7G-control] < [Incognito-MXLI-PD, Incognito-control, Incognito-MXC-GD]; p < 0.001). However, there were no significant differences in SFF among the 3 displacement conditions within each bracket group. Within each displacement condition, the Incognito group demonstrated the highest KFF, followed by the 7G and STb groups ([STb-control, STb-MXLI-PD] < Stb-MXC-GD < 7G-MXLI-PD < [7G-control, 7G-MXC-GD] < [7G-MXC-GD, Incognito-MXLI-PD, Incognito-control] < [Incognito-control, Incognito-MXC-GD]; p < 0.001). MXC-GD exhibited higher KFFs than MXLI-PD in the same bracket group. Conclusions: The slot design and ligation method of the CAD/CAM-LB system should be modified to reduce SFF and KFF during the leveling/alignment stage.

Observation of Surface Morphology and Electrical Properties of Polyurethane Polymer LB Films (폴리우레탄 고분자 LB막의 표면구조 관찰 및 전기적 특성)

  • Seo, Jeong-Yeul;Shin, Hoon-Kyu;Kwon, Young-Soo
    • The Transactions of the Korean Institute of Electrical Engineers C
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    • v.50 no.8
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    • pp.371-375
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    • 2001
  • We attempted to fabricate polyurethane derivatives (PU-CN, PU-DCM) LB films by using LB method. Also, we investigated the monolayer behavior at the air-water interface by surface pressure-area (${\pi}$-A) isotherms. The surface morphologies and the physicochemical properties of LB films were investigated by atomic force microscopy(AFM) and UV-vis spectroscopy, respectively. And, the electrical properties of polyurethane derivatives LB films were investigated by using the conductivity and the dielectric constant. In the surface morphologies, physicochemical and electrical properties of polyurethane derivatives LB films, the properties is different as to the polyurethane derivatives, it is considered that this phenomena could be described by the difference of lumophore pendant which was adhered at PU main chain.

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Fabrication and Properties of OLEDs using PECCP Langmuir-Blodgett(LB) Films (PECCP LB 박막을 이용한 유기 발광 타이모드의 제작과 이의 특성)

  • Lee, Ho-Sik;Lee, Won-Jae;Park, Myung-Gyu;Songe, Min-Jeng;Park, Jong-Wook
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2000.07a
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    • pp.831-834
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    • 2000
  • Characteristics of organic light-emitting diodes(OLEDs) were studied with devices made by PECCP[poly(3,6-N-2-ethylhexyl carbazolyl cyanoterephthalidene)] Langmuir-Blodget(LB) films. The emissive organic material was synthesized and named PECCP, which has a strong electron donor group and an electron accepter group in main chain repeated unit. The LB technique was employed to investigate the identification of the recombination zone in the ITO/PECCP LB films/Alq$_3$/Al structure by varying the LB film thickness. PECCP was considered as an emissive layer and Alq$_3$was used as an electron-transport layer. We measured current-voltage(I-V) characteristics, UV/visible absorption, PL spectrum, and EL spectrum of those devises.

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The Study of Gas Sensor Using Rheological Properties of Polymeric Sensitive LB Films (고분자감응성 LB막의 유변학적인 특성을 이용한 가스센서 연구)

  • 강현욱;김정명;권영수
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 1997.04a
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    • pp.198-201
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    • 1997
  • The new system for identification of organic vapours and analysis method of mechanism between organic vapours and sensitive materials were attempted using the resonant resistance and resonant frequency of Quartz Crystal Analyzer (Q. C. A.). The resonant resistance shift means rheological changes in sensitive LB films occurred by the adsorption of organic vapours, while the resonant frequency shift represent the mass of organic vapour loaded in or on the sensitive LB films. It is thought that we can obtain more accurate response mechanism of organic vapour using the resonant frequency and resonant resistance diagram. The polymeric sensitive material were quantitively depositied using the LB method. In the experimental results, the adsorption behavior of organic vapour response can be decided by two type ; surface adsorption and penetration into sensitive material. Organic vapours had different positions in the Frequency-Resistance (F-R) diagram as to the kinds and concentrations of organic vapours. Thus F-R diagram can be applied to the development of one channel gas sensing system using the Quartz Crystal Analyzer.

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A study on the $NO_2$ Gas Detection Characteristics of Octa-dodecyloxy Copper-phthalocyanine LB Films (Octa-dodecyloxy Copper-phthalocyanine LB막의 $NO_2$ 가스 탐지 특성에 관한 연구)

  • Koo, Ja-Ryong;Lee, Han-Sung;Kim, Young-Kwan;Kim, Jung-Soo
    • Proceedings of the KIEE Conference
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    • 1997.07d
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    • pp.1247-1249
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    • 1997
  • Langmuir-Blodgett(LB) method is one of the ways of fabricating organic ultra thin films. It is well known that It has the advantage to control the alignment and orientation of the molecules in the films. Metallo-phthalocyanines (MPcs) are sensitive to electron affinitive toxic gaseous molecules, such as $NO_2$, NO, $SO_2$. In this study, thin films of octa-dodecyloxy copper-phthalocyanine were prepared by LB method and characterized by using UV/Vis absorption spectroscopy and ellipsometry. Optimal transfer condition of LB films was investigated and preliminary results of current-voltage (I-V) characteristics of these films exposed to $NO_2$ gas as a function of film thickness.

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The Deposition Characterization of DLPC Lipid Membrane Fabricated by Moving wall Type LB Method (Moving wall형 LB법에 의하여 제작된 DLPC 지질막의 누적특성)

  • 이우선;최창주;정용호;김남오;이경섭;장의구;김태성
    • Electrical & Electronic Materials
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    • v.10 no.6
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    • pp.548-554
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    • 1997
  • We fabricated the sample of ultra thin lipid membrane(L-$\alpha$-DLPC) by LB method. The $\pi$-A isotherm of the DLPC was measured at the air-water interface varying with the compressing speed and amounts of solutions for spreading. For the good property of lipid monolayer film, it was necessary to prepare at the lower speed of compressing, with an appropriate volume of solutions for spreading. Absorption, transmitance and intensity with the UV spectrophotometer were measured. The Z-type multilayers showed good characteristics better than Y-type. So we found building-up of structurally high quality LB films is essential to study properties of the films and to get reproducible data.

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A Study on Constructability Improvement of LB-DECK Panel (LB-DECK 패널의 시공성 향상에 관한 연구)

  • Cho, Hyun-Chul;Lho, Byeong-Cheol;Cho, Gyu-Dae;Choi, Kyu-Hyung
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.13 no.2 s.54
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    • pp.122-128
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    • 2009
  • This study is to improve constructability of LB-DECK construction in site such as inconvenience of main and distribution bars in arrangements LB-DECK Panel which is work is applied to many bridges these days as a permanent formwork. So, the constructability is improved by changing the method of allocation of main reinforcing bar and distribution bar which is reviewed for improving efficiency of design and construction process among the suggested methods. The crack shapes, deflections, and strains under static load of the improvement of LB-DECK Panel are compared and analyzed to former LB-DECK Panel. As a result, 13% of strength compared to before the improvement of LB-DECK Panel, and 10% of strength is increased in the case of slab.