• Title/Summary/Keyword: Twisted

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Photoreduction of Methyl Orange Catalyzed by Nile Red-Adsorbed $TiO_2$/Y Zeolites using Visible Light

  • Lee, Jeong-Jin;Kim, Yanghee;Minjoong Yoon
    • Journal of Photoscience
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    • v.8 no.1
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    • pp.27-32
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    • 2001
  • Photoreduction of Methyl Orange Catalyzed by Nile Red-Adsorbed TiO$_2$/Y zeolites. Nile Red was successfully adsorbed on TiO$_2$/Y zeolites and the absorption profile is very broad with maxima, ca. 630 nm. The peak is largely red-shifted compared to that observed in hydrocarbon solvents. Furthermore, a broad and largely Stokes shifted emission band as observed around 660 nm. The largely Stokes shifted emission band should be originated from the excited state structural changes. In order to understand the photocatalytic activities of Nile Red-adsorbed TiO$_2$/Y zeolite, the photoreduction of Methyl Orange(5.0$\times$10$^{-5}$ M) was studied using visible light beyond 320 nm. Methyl Orange was effectively reduced by Nile Red-adsorbed TiO$_2$/Y zeolite, indicating the photocatalytic activity of Nile Red-adsorbed TiO$_2$ zeolites was enhanced by about eight times higher than that of TiO$_2$/Y zeolite.

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Fabrication and Applications of Carbon Nanotube Fibers

  • Choo, Hungo;Jung, Yeonsu;Jeong, Youngjin;Kim, Hwan Chul;Ku, Bon-Cheol
    • Carbon letters
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    • v.13 no.4
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    • pp.191-204
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    • 2012
  • Carbon nanotubes (CNTs) have exceptional mechanical, electrical, and thermal properties compared with those of commercialized high-performance fibers. For use in the form of fabrics that can maintain such properties, individual CNTs should be held together in fibers or made into yarns twisted out of the fibers. Typical methods that are used for such purposes include (a) surfactant-based coagulation spinning, which injects a polymeric binder between CNTs to form fibers; (b) liquid-crystalline spinning, which uses the nature of CNTs to form liquid crystals under certain conditions; (c) direct spinning, which can produce CNT fibers or yarns at the same time as synthesis by introducing a carbon source into a vertical furnace; and (d) forest spinning, which draws and twists CNTs grown vertically on a substrate. However, it is difficult for those CNT fibers to express the excellent properties of individual CNTs as they are. As solutions to this problem, post-treatment processes are under development for improving the production process of CNT fibers or enhancing their properties. This paper discusses the recent methods of fabricating CNT fibers and examines some post-treatment processes for property enhancement and their applications.

UHF RFID Dipole Tag Antenna Design Using Flexible Electro-Thread (도전사를 이용한 UHF RFID 다이폴 태그 안테나 설계)

  • Kim, Yeon-Ho;Chung, You-Chung
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.19 no.1
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    • pp.1-6
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    • 2008
  • A wearable T-matching dipole UHF RFID tag antenna has been designed using conductive electro-thread. The conductivity of the electro-thread has been measured depending on the number of twisted thread. The measured conductivity has been used for simulation to have accurate simulation results. The flexible electro-thread or fabric has been used for fabricating the antenna instead of using copper tape since the electro-thread is more flexible and wearable than copper tape. The return loss and reading range of the fabricated electro-thread UHF RFID tag antennas have been tested. The reading range is approximately 2.4 m.

A Study on the Dressed Shapes of the Blouse with Short Sleeves and Sleeveless according to Arm Movement Using 3-D Scanner (팔 동작에 따른 소매유무별 블라우스 착의형상의 3차원적 파악)

  • Lee, Myung-Hee;Matsuyama, Yoko
    • Fashion & Textile Research Journal
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    • v.8 no.2
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    • pp.209-213
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    • 2006
  • The 3-D information is useful as basic data which has been utilized in the development of simulating technology as fit-simulation. The experiment is designed to take some useful data on the variant shapes which contribute in simulating the adaptability of the clothes. The general figure of the clothes are made after the figure of the basic standing posture of the human body. The shape of the clothes fits with kinetic characteristic of the human body as the form of the clothes gets twisted, the ease of the clothes changes, and the clothes itself expands. We studied the dressed shapes of blouse according to two types of the arm movement(basic posture and reach forward) and three types of clothes(foundation, blouse with short sleeves and sleeveless) in the sit-down-posture. We accomplished some experimental data on three-dimensional measurement of the dressing shapes using TDS-3100 3-D scanner made in Japan PULSTECH. It is considered that the variant of shapes and distribution of gaps in the dressed shapes of blouse are determined by the adaptability of clothes made in arm movement.

Investigation on Forced Vibration Behavior of Composite Main Wing Structure of A Small Scale WIG Craft Excited by Engine and Propeller (엔진 및 프로펠러에 의해 가진되는 소형 위그선 복합재 주날개의 진동 거동 해석)

  • Kong, Chang-Duck;Yoon, Jae-Huy;Park, Hyun-Bum
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.35 no.11
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    • pp.1028-1035
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    • 2007
  • this study, forced vibration analysis was performed on the composite main wing structure of a small scale WIG craft which is equipped two-stroke pusher type reciprocating engine. The structural vibration analysis based on the finite element method was performed using a commercial FEM code, MSC/NASTRAN. Excitations for the frequency response analysis were assumed as the H-mode(horizontal mode), the V-mode(vertical mode) and the X-mode(twisted mode) which are typical main vibration modes of engine. And excitations for the transient response analysis were assumed as the L-mode(longitudinal mode) with the oscillating propeller thrust which occurs.

A Study on the Development of Twist Wheel Type Waste Vinyl Remover (II) - Development of Tractor Attached Vinyl Remover - (Twist Wheel 방식 폐비닐수거기 개발에 관한 연구(II) - 트랙터 부착형 수거기의 개발 -)

  • Ha, Yu-Shin;Park, Kyu-Sik;Kim, Jin-Hyun;Choe, Jung-Seob;Son, Chul-Min;Nam, Sang-Heon;Kim, Tae-Wook
    • Journal of the Korean Society of Manufacturing Process Engineers
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    • v.11 no.2
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    • pp.79-84
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    • 2012
  • This study consist of two parts. One is development of a self-propelling vinyl remover which was already reported at the previous paper. This is the second part of the study. For the study, an attached vinyl remover was developed. It was consisted of connecting tractor to bucket, removing bucket from tractor, and the process was the tractor's assistance hydraulics. In the case of an attached vinyl remover, the vinyl was twisted 0.5times per 30~85cm length. The bobbin's diameter was 190mm and it's stable travelling speed was 1m/s. The revolution of the remover wheel was 90rpm to maintain the wheel's linear velocity. As seen at performance test at the field which had 950mm ridge intervals and 10 a area, the average working speed was 1m/s and the turning time was 20seconds. Therefore, the working performance was 24.5min/10a. The efficiency of used vinyl remover was 97% and working conditions were good.

Liquid Crystal Mixtures of High Response Time and High $T_{NI}$ for LCD-TV Application

  • Ban, Byeong-Seob;Kim, Bong-Hee;Seo, Bong-Sung;Yun, Yong-Kuk;Sakong, Dong-Sik;Chung, Kyu-Ha;Kim, Yong-Bae
    • 한국정보디스플레이학회:학술대회논문집
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    • 2002.08a
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    • pp.498-499
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    • 2002
  • In In order to develop liquid crystal mixtures of high response time and high nematic-isotropic transition temperature ($T_{NI}$) for LCD-TV application, novel liquid crystal molecules with a fluoro-isothiocyanate moiety were synthesized. They showed remarkably high $T_{NI}$ over 200 $^{\circ}C$, wide mesophase range of 170 $^{\circ}C$, high dielectric anisotropy of 14 and high optical anisotropy of 0.19. New LC Mixtures of the high $T_{NI}$ ($85{\sim}100 ^{\circ}C$) and fast response time ($8{\sim}10ms$) were blended with the novel fluoro-isothiocyanate containing LC molecules, phenylcyclohexanes, bicyclohexanes and ester compounds. It was also studied on optimum pitch of liquid crystal for high speed twisted nematic LCD-TV applicaton. The LC mixtures show a fast speed of the below one frame rate in real 17" TV panel.

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Liquid Crystal Mixtures of High Response Time and High $T_{NI}$ for LCD-TV Application

  • Ban, Byeong-Seob;Kim, Bong-Hee;Seo, Bong-Sung;Yun, Yong-Kuk;Sakong, Dong-Sik;Chung, Kyu-Ha;Kim, Yong-Bae
    • 한국정보디스플레이학회:학술대회논문집
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    • 2002.08a
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    • pp.413-414
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    • 2002
  • In In order to develop liquid crystal mixtures of high response time and high nematic-isotropic transition temperature ($T_{NI}$) for LCD-TV application, novel liquid crystal molecules with a fluoroisothiocyanate moiety were synthesized. They showed remarkably high $T_{NI}$ over 200 $^{\circ}C$, wide mesophase range of 170 $^{\circ}C$, high dielectric anisotropy of 14 and high optical anisotropy of 0.19. New LC Mixtures of the high $T_{NI}$ (85${\sim}$100 $^{\circ}C$) and fast response time (8${\sim}$10ms) were blended with the novel fluoroisothiocyanate containing LC molecules, phenylcyclohexanes, bicyclohexanes and ester compounds. It was also studied on optimum pitch of liquid crystal for high speed twisted nematic LCD-TV applicaton. The LC mixtures show a fast speed of the below one frame rate in real 17" TV panel.

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Cell Gap Dependent Electrode-Optic Characteristics of Fringe-Field Switching Mode using a Liquid Crystal with Negative Dielectric Anisotropy (유전율 이방성의 음인 액정을 이용한 Fringe-Field Switching mode의 cell gap 변화에 따른 전기광학 특성)

  • 정송희;김향율;이종문;이승희
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.16 no.10
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    • pp.914-922
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    • 2003
  • The FFS (fringe-field switching) mode was known to exhibit both a wide viewing angle and high transmittance, especially when using a liquid crystal with negative dielectric anisotropy. We have studied cell gap-dependent electrode-optic characteristics of the FFS mode using the LC with negative dielectric anisotropy. In case of a small cell gap of 2 ${\mu}$m, the transmittance at the center of pixel and common electrodes is relatively low because effect of surface anchoring that holds the LC to the initial state is larger than that in a large cell gap of 4 .urn such that the LCs in those regions cannot rotate enough. However, in case of a large cell gap of 4 .urn, the effect of surface anchoring becomes relatively small so that the LCs at the center of pixel and common electrode can be twisted enough by applied voltage, giving rise to high transmittance. Therefore, we can conclude that the light efficiency is dependent on the cell gap.

Building the Governance between the Public and Private Sectors for the Success of Community Welfare Alliance: Centering on the Analysis of AHP (지역사회복지협의체의 성공적 정착을 위한 공공과 민간의 Governance구축에 관한 연구 : AHP분석을 중심으로)

  • Kim, Chang-Ki;Jung, Jae-Wook
    • The Journal of the Korea Contents Association
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    • v.9 no.3
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    • pp.262-269
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    • 2009
  • The public and private sectors have quite different views on the operation of community welfare alliance. Their understanding of the issues has a vast difference, which may lead to twisted operation of the community welfare alliance. In fact, there are many areas that have troubles in the operation of the alliance. This study systematically analyzes limitations that the alliance has and it goals to draw out improvement policies to overcome them. As a study method, a survey is conducted on the leaders of community welfare alliance to suggest an AHP analysis model on the issue awareness and improvement policy. Concentrated on the analyzed results and implications entailed through the analysis, this study suggests improvement policies to overcome such limitations that the community welfare alliance has.