• 제목/요약/키워드: wet processing

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Fabrication of Organic Thin-Film Transistor Using Vapor Deposition Polymerization Method (Vapor Deposition Polymerization 방법을 이용한 유기 박막 트렌지스터의 제작)

  • 표상우;김준호;김정수;심재훈;김영관
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2002.07a
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    • pp.190-193
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    • 2002
  • The processing technology of organic thin-film transistors (Ons) performances have improved fur the last decade. Gate insulator layer has generally used inorganic layer, such as silicon oxide which has properties of a low electrical conductivity and a high breakdown field. However, inorganic insulating layers, which are formed at high temperature, may affect other layers termed on a substrate through preceding processes. On the other hand, organic insulating layers, which are formed at low temperature, dose not affect pre-process. Known wet-processing methods for fabricating organic insulating layers include a spin coating, dipping and Langmuir-Blodgett film processes. In this paper, we propose the new dry-processing method of organic gate dielectric film in field-effect transistors. Vapor deposition polymerization (VDP) that is mainly used to the conducting polymers is introduced to form the gate dielectric. This method is appropriate to mass production in various end-user applications, for example, flat panel displays, because it has the advantages of shadow mask patterning and in-situ dry process with flexible low-cost large area displays. Also we fabricated four by four active pixels with all-organic thin-film transistors and phosphorescent organic light emitting devices.

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Analysis of Cutter and Design of Chip Processing System for Large Scale Machine Tool (대형 공작기계용 칩 처리시스템 설계 및 커터 해석)

  • Lee, Jong-Moon;Yang, Young-Joon
    • Journal of the Korean Society of Manufacturing Process Engineers
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    • v.11 no.4
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    • pp.147-153
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    • 2012
  • The demands of the large scale machine tools, for instance, such as planomiller, turning machine, boring machine, NC machine, have been gradually increased in recent years. As the performances of machine tools and/or cutting tools are advanced, it is possible to perform high-speed and high-precision cutting works. The effective treatment of wet chip, which is discharged from cutting works, becomes very important problems. Therefore, this study is forced on the design of large scale machine tools using CATIA V5R18 and analysis of cutter, which is considered as essential equipment in large scale machine tools, using MSC.Nastran & MSC.Patran. Especially, the relations between tolerated load of cutter, driving horse power and rpm of driving shaft in chip processing system are investigated through analysis. As the results, the reliability of design could be improved by evaluating simulated numerical values, it showed that tolerated loads of supported part and edged part of cutter are 87,000N and 14,450N, respectively.

Fabrication of YBCO films in MOD processing via chemically modified precursor solution (화학적으로 변형된 전구용액을 이용한 YBCO 박막 제조)

  • Kim, Y.K.;Yoo, J.M.;Chung, K.C.;Ko, J.W.;Kim, Y.J.;Han, B.S.
    • Progress in Superconductivity
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    • v.7 no.2
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    • pp.158-161
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    • 2006
  • Superconducting YBCO films were successfully fabricated by MOD process using chemically modified precursor solution. In this study, a chemically modified precursor solution for MOD processing was synthesized using metal-organic salts and organic additives. It was shown that crack-free and uniform precursor films were formed after calcination in humidified Oxygen atmosphere. Less than 3 hours are required to finish the calcination process. XRD measurement shows that $BaF_2,\;CuO,\;Y_2O_3$ are major constituent of precursor films. Furthermore, YBCO films without any secondary phases were successfully fabricated after annealing in wet $Ar/O_2$ atmosphere. The YBCO film prepared on a $LaAlO_3$ single crystal substrate ($10mm{\times}10mm$) gives transport $I_c$ of 10A at 77K. This chemical modification approach is a possible candidate for improving MOD-processing of YBCO coated conductor.

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CMP (Chemical Mechanical Polishing) characteristics of langasite single crystals for SAW filter applications

  • Jang, Min-Chul;An, Jin-Ho;Kim, Jong-Cheol;Auh, Keun-Ho
    • Journal of the Korean Crystal Growth and Crystal Technology
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    • v.10 no.4
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    • pp.309-317
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    • 2000
  • Langasite is a promising new piezoelectric material for SAW filter application. Little was known until recently about the methods needed to mechanically polish and chemically polish/etch this material. In this experiment, polishing, slurry chemistry and chemical wet etching for langasite is described. Conventional quartz and LN ($LiNbO_3$) polishing methods did not produce satisfactory polished surfaces, and polishing with a colloidal silica slurries has shown to be most effective. The optimum condition was investigated by changing the slurry chemistry. As the planarization effect is very important in SAW filter applications, the examination of the effective particle number effect and the particle size effect was carried out. Z-cut langasite surface which had been polished with the colloidal silica slurries was etched in a variety of etchants. Conventional quartz etchants destroyed the polished surface. Other etchants formed a thin film on the surfaces. In this experiment, the reaction between langasite and a few etching solution was analysed. And an appropriate selective etchant solution for analyzing the defects was synthesized.

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Fabrication of YBCO films in MOD processing using F-free Cu precursor solution (F-free 구리 전구용액을 이용한 YBCO 박막 제조)

  • Kim Young-Kuk;Yoo Jaimoo;Ko Jae-Woong;Chung Kuk Chae;Kim Young-Jun;Han Bong-Soo
    • Progress in Superconductivity and Cryogenics
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    • v.7 no.3
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    • pp.5-8
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    • 2005
  • Superconducting YBCO films were successfully fabricated by MOD process using F-free Cu precursor solution. In this study. a chemically modified precursor solution for MOD Processing was synthesized using metal-organic salts and F-free Cu precursor. It was shown that crack-free and uniform precursor films were formed after calcination in humidified oxygen atmosphere. Less than 3 hours are required to finish the calcination process. XRD measurement shows that $BaF_2,\;CuO,\;Y_2O_3$ are major constituent of precursor films. Furthermore. YBCO films without any secondary phases were successfully fabricated after annealing in wet $Ar/O_2$ prepared on a $LaA1O_3$ single crystal substrate $(10mm{\times}10mm)$ gives transport Ic of 10A at 77K. This chemical modification approach is a possible candidate for improving MOD-processing of YBCO coated conductor.

Overview of Fisheries Resources in Namibia

  • Endjala, Jason Tshuutheni
    • Journal of Marine Bioscience and Biotechnology
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    • v.3 no.1
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    • pp.31-37
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    • 2008
  • Off the 1,572 km long coastline of Namibia lies known as the Benguela upwelling system, a very rich source of marine life supporting traditional and modern forms of fishery. Commercial fishing and fish processing is one of the fastest-growing sectors of the Namibian economy in terms of employment, export earnings, and contribution to GDP. The fishing industry has grown to the extent that it is currently Namibia's second biggest export earner of foreign currency after mining (90% of national output is marketed for export). In 2005, Namibia harvested about 552,164 tonnes of fish. The final value of processed products (export value) that year was around US$ 376.0 million. Besides the marine captured fisheries, Namibia also has a small but vibrant aquaculture sector. Inland captured fisheries exist in the north-east and north-west of Namibia where as commercial freshwater aquaculture of tilapia and catfish is also undertaken. The inland fisheries are mainly subsistence based and typically labour intensive, with low catch per unit effort. However the subsistence fisheries from these regions play a significant role in the lives of rural community. The domestic market for marine fish products is extremely limited due to the small size of the population (2 million). The fishing industry is a source of considerable employment for many Namibians. Huge potential to increase production exists in Namibia, unpolluted high quality marine waters, high natural primary productivity of the seawater, availability of inexpensive fish by-products from established fish processing sector for inclusion in wet aqua-feeds and well-established processing, packaging and marketing systems due to the marine capture fisheries that can be adopted for aquaculture purpose.

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Development of Optimum Processing Conditions in Air Dried Garlics Using Response Surface Methodology (반응표면 분석법을 이용한 마늘 열풍건조 공정의 최적화)

  • 김명환;김병용
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.19 no.3
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    • pp.234-238
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    • 1990
  • The effects of salt concentration immersion time in a salt solution prior to air dehydration and heating of air temperature during dehydration upon the browning reaction and pyruvic acid content of air dried garlics to a 6.5% moisture content(wet basis) were analyzed by a response surface methodology(RSM), Those values were also predicted by using a second degree polynomial regression model. Heating of air temperature was the most significant factor affecting the both browning reaction and pyruvic acid content. Salt concentration had more influence to browning reaction than immersion time whereas immersion time was more impor-tant factor than salt concentration on a retention of pyruvic acid sugested different processing conditions. While the processing conditions to minimize the browning reaction(O.D=0.009) were 0.3% of salt solution 9 min of immersion time and 5$0^{\circ}C$ of air temperature compared to control(O.D=0.022) of air dehydration at 5$0^{\circ}C$ Pyruvic acid contents were maximized(174 $\mu$mole/g garlic solid) at the 0.1% of salt solution 3 min of immersion time and 5$0^{\circ}C$ of air temperature compared to control(147 $\mu$mole/g garlic solid) of air dehydration at 5$0^{\circ}C$

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Fabrication of YBCO films in MOD processing using F-free Y & Cu precursor solution (F-free Y & Cu 전구용액을 이용한 YBCO 박막 제조)

  • Kim, Young-Kuk;Yoo, Jai-Moo;Ko, Jae-Woong;Chung, Kook-Chae;Kim, Young-Jun;Han, Bong-Soo;Wang, X.L.;Dou, S.X.
    • Progress in Superconductivity and Cryogenics
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    • v.8 no.1
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    • pp.15-18
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    • 2006
  • A new precursor solution wilt low fluorine content was synthesized for MOD processing of coated conductors. In this study, the precursor solution for MOD processing was synthesized using F-free yttrium and copper precursor. It was shown that crack-free and uniform precursor films were formed after calcination in humidified oxygen atmosphere. Less than 2 hours were required to finish the calcination process. The relatively gradual weight loss during the calcination process is attributed to the feasibility of fast calcination profile. The calcined precursor film was converted to a YBCO film without any secondary phases after annealing in wet $Ar/O_2$ atmosphere. Fully converted film shows uniform microstructure and high critical current density. $(Jc=2.7MA/cm^2) $.

The Characteristic Studies of Powder Coating System in Wet Slurry Processing Powder Foundation (습식공정 파우더 파운데이션에서 파우더 코팅 시스템의 특성 연구)

  • Lee, Chan-Ki;Lee, Su-Jin;Choi, Jae-Wook;Choi, Yeong-Jin;Han, Shang-Hoon
    • Journal of the Society of Cosmetic Scientists of Korea
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    • v.36 no.3
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    • pp.227-231
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    • 2010
  • Among various make-up products, foundations are widely used to express clear and flawless skin. Foundations can be classified by its formula to 3 types, liquid foundation, powder foundation, and oil dispersion foundation. Powder foundations are easy to carry and use, so it is commonly possessed. In the R&D point of view, the developing method of powder foundations can be classified again to 3 types. Dry-process, baked-process, and the wet slurry-process. The fact that the wet slurry-process goes through either the back injection method or the front injection method is previously known. The front injection process is used as the main method in this study. We observed the quality dependence on the kind of solvent and the powder coating system. In brief, when water was used as the main solvent, the hardness increased than when volatile silicones or hydrocarbons were used. And the sensory results were shown to prefer volatile solvents (silicones or hydrocarbons) over water. Similarly, when the amino acid-coating system was applied, the hardness was shown to increase, when silicone-coating system shown no specific change. By these results, tailor-made powder foundations targeting specific customer grades can be easily produced.

Comparison of the Migration and Absorption of Calcium and Magnesium in Apple Leaves Sprayed with Plant Nutrients Prepared by Wet Nano-grinding Technology (습식 나노화 공정기술 적용 식물 영양제를 살포한 사과의 칼슘과 마그네슘 이동 및 흡수율 비교)

  • Park, Jae-Ryoung;Kim, Eun-Gyeong;Lee, Seung Hyun;Chung, Il Kyung;Kim, Kyung-Min
    • Journal of Life Science
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    • v.29 no.7
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    • pp.769-773
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    • 2019
  • In this study, the migration route and the absorption rate of calcium and magnesium in apple leaves were compared and analyzed using plant nutrients prepared by wet nano-grinding technology. The plant nutrients were sprayed onto the leaves to confirm the component content and the movement route of the nanoized calcium and magnesium. At 2, 4, and 8 weeks after the plant nutrient treatment, the apple leaves were divided into petiole, lamina, and side, and SEM and EDS were used to measure the calcium and magnesium contents. The calcium and magnesium contents of the petiole increased from the 4th week after plant nutrient application to 1,115% at the 8th week. The calcium and magnesium contents of the lamina decreased after spraying but increased after 4 weeks. The calcium and magnesium contents increased in the side of the leaves compared to the control, reaching 673% after 4 weeks. The calcium and magnesium contents increased with increasing duration in all plots when compared with the control unsprayed leaves, suggesting that the usually poorly soluble calcium and magnesium were transferred from the petioles to the lamina. The results of this study indicate that improved calcium and magnesium absorption could be obtained in crops other than apples using plant nutrients produced through wet nano-processing technology. This technology is also expected to be applicable to natural products and bioindustries.