• Title/Summary/Keyword: photo

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Photoinitiator-free Photo-reactive Coloration of Wool Fabrics Using C.I. Reactive Black 5

  • Dong, Yuanyuan;Jang, Jin-Ho
    • Textile Coloration and Finishing
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    • v.24 no.2
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    • pp.97-105
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    • 2012
  • Compared with conventional adsorption-based coloration, the photoreactions of dyes such as photo-copolymerization and photo-crosslinking under UV irradiation can be employed for the coloration of textiles, which can be carried out without salt addition at room temperature. C.I. Reactive Black 5, a homo-bifunctional reactive dye containing two sulfatoethylsulfone groups, is used as a photo-reactive dye for wool fibers. Upon UV irradiation, the photo-reactive dye was grafted onto wool fabrics without photoinitiators. Since the disulfide bonds in the cystine residues of wool can be easily photodecomposed to active thiyl radicals which initiate the polymerization, the dye can be polymerized to an oligomeric dye of a degree of polymerization of 12 or more. The grafted fabrics reached a grafting yield of 2.3% o.w.f. and a color yield (K/S) of 18.2 by the photografting of an aqueous dye concentration of 9% using a UV energy of 25J/$cm^2$. Furthermore, the photochemically dyed wool fabric showed higher colorfastness properties to light, laundering and rubbing comparable to conventional reactive dyeing.

The High Efficiency of Amorphous-Si Solar Cells Prepared by Photo-CVD System (광(光) CVD 법(法)에 의한 a-Si 태양전지(太陽電池)의 고효율화에 관한 연구(硏究))

  • Kim, Tae-Seoung
    • Solar Energy
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    • v.5 no.2
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    • pp.46-53
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    • 1985
  • Hydrogenated amorphous silicon solar cells which are fabricated by photo-chemical vapor deposition (photo-CVD) system has been investigated. In the photo-CVD system which consists of three separate reaction chambers, low-pressure mercury lamp has been used as a light source. The main reactant ($Si_2H_6/He$) gases which are premixed with a small amount of mercury vapor in a mercury-vaporizer kept at $50^{\circ}C$ have been used. Using $C_2H_2$ and $SiH_2(CH_3)_2$ as the carbon source, p-type wide band gap a-SiC:H films have been obtained. The result has been found that the undoped layers of the pin/substrate solar cells are influenced by the residual impurities, such as phosphorus and boron during the deposition process. By minimizing the effect of the impurities in the i-layer and optimizing conditions at the p-layer and p/i interface, the energy conversion efficiency of 9.61 % under AM-1 ($100mW/Cm^2$) has been achieved for pin/substrate solar cells illuminated through their p-layers, using the three separate reaction chamber apparatus. It is expected that a-SiC:H solar cells with the energy conversion efficiency over 10% have been fabricated by Photo-CVD method.

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Optimal Resolution of Aerial Photo for Construction of Image Database (영상데이타베이스 구축을 위한 항공사진의 최적해상도)

  • Lee, Hyun-Jik;Lee, Seung-Ho;Park, Hong-Gi
    • Journal of Korean Society for Geospatial Information Science
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    • v.8 no.2 s.16
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    • pp.89-99
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    • 2000
  • The Quality and Accuracy of digital image is important factor for decision of accuracy in digital photogrammetry because all the inside works in digital photogrammetry are based on digital image. But it is still difficult to ensure quality assurance and appication of data because there is no distinct criterion about quality and accuracy of digital image when the works in digital photogrammetry is accomplished. This study presents optimal resolution of aerial photo through error analysis of image coordinate using auto inner orientation in digital photograrnrnetry workstation. In second step, we are valified to optimum resolution of aerial photo image with orientation analysis. Finally, we are established to validity optimal resolution of aerial photo image with production of ortho image and mosaic image using optimal resolution aerial photo image.

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The Effect of Temperature and Photoinitiator Concentration on Conversion of Photopolymerized Multiethylene Glycol Dimethacrylate by Photo-DSC (Photo-DSC를 사용한 에틸렌글리콜 단위 길이에 따른 다이메타크릴레이트의 광중합 전환률에 미치는 온도와 광개시제 농도의 영향)

  • Do, Hyun-Sung;Kim, Dae-Jun;Kim, Hyun-Joong;Lee, Young-Kyu
    • Journal of Adhesion and Interface
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    • v.4 no.3
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    • pp.14-20
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    • 2003
  • In order to study the radiation curing behavior of poly(ethylene glycol 400) dimethacrylate and ethylene glycol dimethacrylate, we investigated the influence of temperature and photoinitiator concentration by photo-DSC. As the number of ethylene glycol unit, the concentration of photoinitiator, and the reaction temperature increased, the reaction speed of PEG400DMA and EGDMA increased. Although the reaction speed of PEG400DMA was lower than EGDMA, the overall conversion of PEG400DMA was high.

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Cruciform Thiophene-based Molecules as Organic Semiconductors for Field Effect Transistor Applications

  • Choi, Dong-Hoon;Kim, Dae-Chul;Kim, Kyung-Hwan;Cho, Min-Ju;Jin, Jung-Il
    • 한국정보디스플레이학회:학술대회논문집
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    • 2007.08a
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    • pp.170-173
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    • 2007
  • Cruciform conjugated molecule, 4(DP3T)-benzene bearing terthiophene moieties has been synthesized through Horner-Emmons Reaction using 5-dodecyl-5"-aldehyde-[2,2';5',2"] terthiophene as dendrons and octaethyl benzene- 1,2,4,5-tetrayltetrakis(methylene)tetraphosphonate as the core unit; this molecule has been fully characterized. The terthiophene-based molecule exhibits good solubility in common organic solvents and good self-film forming property. They are intrinsically crystalline as they exhibit well-defined X-ray diffraction patterns from uniform orientations of molecules. Thus, intermolecular interaction can be enhanced to affect the carrier transport phenomena after annealing at $148^{\circ}C$. The semiconducting property of 4(DP3T)-benzene have been evaluated in organic field-effect transistors. 4(DP3T)-benzene exhibit carrier mobility as high as $(6.6{\pm}0.5)$ ${\times}$ $10^{-6}cm^2V^{-1}s^{-1}$.

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Accuracy Assessment Geoposition of Airborne Line-Scanner Image (라인방식 디지털 항공 카메라영상의 위치 정확도 평가)

  • Cho, Han-Kun;Wie, Gwang-Jae;Choi, Yun-Soo;Lee, Sang-Jin
    • Spatial Information Research
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    • v.19 no.1
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    • pp.51-59
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    • 2011
  • We produced true ortho images after interpolating occlusion areas and relief displacement of building as well as producing ortho-images to use backward image of ADS which is a aerial digital camera of line type. Also, I was able to produce high quality ortho-images using a small mount of Ground Control Points(GCP) relatively to compare to frame type camera from the evaluation of horizontal position accuracy using ground check points, photo control points for the verification of ortho-images and true-ortho images. Also, I was able to verify the effectiveness in interpolating occlusion areas cause the length overlap was 100% when producing true-ortho images of line type camera.

A Comparative Study on the Measurement of Smoke from Diesel Vehicle on Chassis-dynamometer using Reflection Photo and Light Extinction Method (차대 동력계에서의 디젤 차량의 매연 측정을 위한 여지 반사식 및 광투과식 측정법의 비교 연구)

  • Kim, Ju-Chul;Lee, Choong-Hoon
    • Journal of the Korean Society of Safety
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    • v.22 no.6
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    • pp.13-19
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    • 2007
  • Diesel car's smoke measurement equipment and method were investigated based on the exhaust gas regulations. Reflection photo method and light extinction method for measuring smoke were compared under conditions of both no load mode and Lug-down 3 mode. Free acceleration mode at no load condition was used for regular inspection of diesel car, and Lug-down 3 mode was used for fine inspection of the diesel car. A correlation between no load mode and Lug-down 3 mode was investigated in this research. The smoke measured with reflection photo method was 1.5${\sim}$2 times higher than that of light extinction method The correlation coefficient between reflection photo method and light extinction method for measuring smoke was 0.83, which shows comparatively high correlation between the two methods for measuring smoke in diesel engines.

Degradation of Dye Wastewater by Advanced Oxidation Process: A Comparative Study (고급산화공정에 의한 안료폐수 처리: 비교 연구)

  • Park Young-Seek
    • Journal of Environmental Science International
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    • v.15 no.1
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    • pp.67-75
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    • 2006
  • The degradation of Rhodamine B (RhB) in water was investigated in laboratory-scale experiments, using five advanced oxidation Processes (AOPs) $UV/H_2O_2$, lenten, photo-lenten, $UV/TiO_2,\;UV/TiO_2/H_2O_2$. The photodegradation experiments were carried out in a fluidized bed photoreactor equipped with an immersed 32 W UV-C lamp as light source. initial decolorization rate and COD removal efficiency were evaluated and compared. The results obtained showed that the initial decolorization rate constant was quite different for each oxidation process. The relative order of decolorization was: photo-fenton > $UV/TiO_2/H_2O_2$ > fenton > $UV/H_2O_2$ > $UV/TiO_2$ > UV > $H_2O_2$. The relative order of COD removal was different from decolorization: photo-fenten ${\fallingdotseq}$ $UV/TiO_2/H_2O_2\;>\;UV/TiO_2\;>\;fenton\;>\;UV/H_2O_2$. The Photo-lenten and $UV/TiO_2/H_2O_2$ processes seem to be appropriate for decolorization and COD removal of dye wastewater.

Social Media Fake News in India

  • Al-Zaman, Md. Sayeed
    • Asian Journal for Public Opinion Research
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    • v.9 no.1
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    • pp.25-47
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    • 2021
  • This study analyzes 419 fake news items published in India, a fake-news-prone country, to identify the major themes, content types, and sources of social media fake news. The results show that fake news shared on social media has six major themes: health, religion, politics, crime, entertainment, and miscellaneous; eight types of content: text, photo, audio, and video, text & photo, text & video, photo & video, and text & photo & video; and two main sources: online sources and the mainstream media. Health-related fake news is more common only during a health crisis, whereas fake news related to religion and politics seems more prevalent, emerging from online media. Text & photo and text & video have three-fourths of the total share of fake news, and most of them are from online media: online media is the main source of fake news on social media as well. On the other hand, mainstream media mostly produces political fake news. This study, presenting some novel findings that may help researchers to understand and policymakers to control fake news on social media, invites more academic investigations of religious and political fake news in India. Two important limitations of this study are related to the data source and data collection period, which may have an impact on the results.

A Study on SU-8 Fabrication Process for RF and Microwave Application (RF 및 Microwave 응용을 위한 SU-8 공정 연구)

  • Wang, Cong;Kim, Nam-Young
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2009.06a
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    • pp.65-66
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    • 2009
  • This paper describes a procedure developed to fabricate negative photo resist SUMS to a semi-insulating (SI)-GaAs-based substrate. SU-8 is attractive for micromachine multi-layer circuit fabrication, because it is photo-polymerizable resin, leading to safe, and economical processing. This work demonstrates SUMS photo resist can be used for RFIC/MMIC application.

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