• Title/Summary/Keyword: micron size

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Preparation of S-keratose/PVA Nonwoven Webs by Electrospinning (전기방사를 이용한 S-keratose/PVA 부직포의 제조)

  • Park Hyunsu;Song Kyung Geun
    • Textile Coloration and Finishing
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    • v.17 no.1
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    • pp.45-51
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    • 2005
  • Soluble keratose(S-keratose) could be obtained by oxidizing the wool keratin with performic acid. S-keratose/PVA solutions were made by dissolving them in the formic acid and S-keratose/PVA web of sub-micron size was made by electro-spinning technique. SEM, elemental analysis, FT-IR, X-ray diffractometry, and TGA were used to characterize the properties of S-keratose/PVA solutions and fibers. As the S-keratose content in S-keratose/PVA solution increased, viscosity of solution decreased while electrical conductivity has increased. The fiber diameter has decreased with increasing the S-keratose content. S-keratose/PVA ratio in fibers were similar to the ratio in the solutions. The crystalline structures of S-keratose and PVA existed separately in the electrospun webs. Thermal stability of the web increased with the PVA content increasing.

Preparation of S-keratose/Nylon 6 Nonwoven Webs by Electrospinning (전기방사를 이용한 S-keratose/Nylon 6 부직포의 제조)

  • Kim Jin-Won;Song Kyung Geun
    • Textile Coloration and Finishing
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    • v.17 no.1
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    • pp.38-44
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    • 2005
  • Oxidation method was used to extract S-keratose from wool. Wool was treated with performic acid and soluble fraction(S-keratose) was collected by evaporating the solvent. S-keratose and Nylon 6 were dissolved in formic acid at the ratio of 100/0, 80/20, 50/50, 20/80, and 0/100, and S-keratose/Nylon 6 web of sub-micron size was made by electro-spinning technique. SEM, EA, FT-IR, XRD, and TGA were used to characterize the properties of S-keratose/Nylon 6 solutions and electrospun fibers. As the Nylon 6 content increased, viscosity, conductivity of the electrospinning solution and the diameter of spun fiber increased. Electrospun nonwoven webs have the same S-keratose/Nylon 6 ratios of the spinning solutions. The crystalline structures of S-keratose and Nylon 6 existed separately in the electrospun webs. Thermal stability of the webs increased due to Nylon 6 content.

Image Detecting System for Pinhole with Photoelectric Sensors (광전(光電)센서를 활용한 핀홀의 영상검출시스템)

  • Kang, Min-Goo;Zo, Moon-Shin;Jeon, Jong-Suh
    • Journal of Internet Computing and Services
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    • v.13 no.3
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    • pp.17-22
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    • 2012
  • In this paper, a photoelectric image detection system is proposed using an APD(Avalanche Photodiode) sensor, a LED illuminator, and fiberoptic waveguides. This proposed pinhole detection system can detect the pinholes of 100 micron with the speed rate of 1,000mpm(meter per minute). And detecting performance of image system is improved by the SQL based DB analysis of classifying pinhole's detected location and size using image detection algorithms.

Synthesis of Two-Component Titanate Powders Using Ethylene Glycol Solution (에틸렌글리콜 용액을 이용한 2성분계 Titanate 분말의 합성)

  • 이상진;권명도
    • Journal of Powder Materials
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    • v.9 no.5
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    • pp.346-351
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    • 2002
  • Pure and fine, two-component titanate powders (barium titanate, calcium titanate etc.) were synthesized by an ethylene glycol method. Titanium isopropoxide and other metal ionic salts were dissolved in liquid-type ethylene glycol without any precipitation. In non-aqueous system, the amount of ethylene glycol affected the solubility and homogeneity of metal cation sources in the solution. At the optimum amount of the polymer, the metal ions were dispersed effectively in solution and a homogeneous polymeric network was formed. Most of the synthesized powders had sub-micron or nano-size primary particles after calcination and the agglomerated calcined powders were easily ground by ball milling process. All synthesized titanate powders had stable crystallization behavior at low temperature and high specific surface area after ball milling. The crystallization behavior and the microstructures of the calcined powders were affected on the ethylene glycol content.

New Morphology of Conducting Polythiophene

  • Karim Mohammad Rezaul;Lee Chul-Jae;Kim Hee-Jin;Bhuiyan Md Tauhidul Islam;Lee Mu-Sang
    • Proceedings of the Polymer Society of Korea Conference
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    • 2006.10a
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    • pp.286-286
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    • 2006
  • We report on a fascinating morphology; giant spherical conducting polythiophene by the in-situ gamma radiation-induced chemical polymerization method. The resultant micron-size buckyball-shaped polymer structures were identified by high resolution transmission electron microscopy and scanning electron microscopy. Different characterizations e.g. Fourier transform infrared, x-ray diffraction, and x-ray photoelectron microscopy were utilized to prove that the new morphological conducting polythiophene was synthesized successfully by this novel method.

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Analysis of Wear Debris on the Lubricated Machine Surface by the Neural Network (Neural Network에 의한 기계윤활면의 마멸분 해석)

  • 박흥식
    • Tribology and Lubricants
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    • v.11 no.3
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    • pp.24-30
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    • 1995
  • This paper was undertaken to recognize the pattern of the wear debris by neural network as a link for the development of diagnosis system for movable condition of the lubricated machine surface. The wear test was carried out under different experimental conditions using the wear test device was made in laboratory and wear testing specimen of the pin-on-disk type were rubbed in paraffine series base oil, by varying applied load, sliding distance and mating material. The neural network has been used to pattern recognition of four parameter (diameter, elongation, complex and contrast) of the wear debris and learned the friction condition of five values (material 3, applied load 1, sliding distance 1). The three kinds of the wear debris had a different pattern characteristic and recognized the friction condition and materials very well by the neural network. The characteristic parameter of the large wear debris over a few micron size enlarged recognition ability.

Photo-pumped $1.3\;{\mu}m$ vertical-cavity surface-emitting lasers (광펌핑하여 $1.3\;{\mu}m$파장에서 동작하는 수직공진 표면광 레이저)

  • 송현우;김창규;이용희
    • Korean Journal of Optics and Photonics
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    • v.8 no.2
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    • pp.111-115
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    • 1997
  • Vertical-cavity surface-emitting laser(VCSEL)s operating at 1.3-micron wavelength for optical communication are fabricated by using Si/SiO$_2$dielectric quater-wave pairs on both sides of the InGaAsP(${\lambda}_g$=1.3 ${\mu}{\textrm}{m}$) gain material. VCSELs are optically pumped with a Nd-YAG laser in a pulsed mode and lasing around 1.3 microns is observed. Lasing characteristics such as threshold pump intensity as a function of mirror-reflectivity, polarization, and threshold pump density with pump spot size are investigated.

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Plasmonic Color Filter with Robustness Against Cross Talk for Compact Imaging Applications

  • Cho, Hyo Jong;Do, Yun Seon
    • Current Optics and Photonics
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    • v.4 no.1
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    • pp.16-22
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    • 2020
  • In high resolution imaging devices, smaller aperture in the color filter causes cross talk which provides incorrect information. Plasmonic color filters (PCFs) have been reported as an alternative of the conventional color resist based-color filter (CRCF) and many studies on PCFs demonstrated the filtering function by PCFs with a sub-micron size. In this work, we investigated the cross talk performance of PCFs compared to CRCFs. The effect of cross talk over distance from the filter were measured for each filter. Despite poorer spectral filtering characteristics, PCFs were more robust against cross talk than CRCFs. Also, the further away from the filter, the more cross talk appeared. As a result, PCFs showed less cross talk than CRCFs at about 82% of the results measured at a distance of 2~10 ㎛. This study will help to make practical use of PCFs in high-resolution imaging applications.

VLSI Implementation of H.264 Video Decoder for Mobile Multimedia Application

  • Park, Seong-Mo;Lee, Mi-Young;Kim, Seung-Chul;Shin, Kyoung-Seon;Kim, Ig-Kyun;Cho, Han-Jin;Jung, Hee-Bum;Lee, Duk-Dong
    • ETRI Journal
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    • v.28 no.4
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    • pp.525-528
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    • 2006
  • In this letter, we present a design of a single chip video decoder called advanced mobile video ASIC (A-MoVa) for mobile multimedia applications. This chip uses a mixed hardware/software architecture to improve both its performance and its flexibility. We designed the chip using a partition between the hardware and software blocks, and developed the architecture of an H.264 decoder based on the system-on-a-chip (SoC) platform. This chip contains 290,000 logic gates, 670,000 memory gates, and its size is $7.5\;mm{\times}7.5\;mm$ (using 0.25 micron 4-layers metal CMOS technology).

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Synthesis and Microstructure of Cu/VSZ Composite for High Temperature Electrolysis Cathode (고온수전해 수소극용 Cu/YSZ 복합체의 제조 및 미세구조)

  • Kim, Jong-Min;Jung, Hang-Chul;Kang, An-Soo;Hong, Hyun-Seon
    • Transactions of the Korean hydrogen and new energy society
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    • v.18 no.3
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    • pp.238-243
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    • 2007
  • The composite powder of Cu and YSZ was synthesized for a high temperature electrolysis cathode by mechanical milling. The average Cu particle size was reduced to 5 micro-meter from 48 micro-meter after the mechanical ball milling. The composite powder showed that Cu particles were uniformly covered with finer YSZ particles. Sub-micron sized pores were uniformly dispersed in the Cu/YSZ composit. Homogeneously-dispersed fine YSZ in the composite is expected to the increase in triple phase boundaries, thereby leading the enhanced performance of cathode.