• Title/Summary/Keyword: 3D manufacturing

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Highly Efficient Thermal Plasma Scrubber Technology for the Treatment of Perfluorocompounds (PFCs) (과불화합물(PFCs) 가스 처리를 위한 고효율 열플라즈마 스크러버 기술 개발 동향)

  • Park, Hyun-Woo;Cha, Woo Byoung;Uhm, Sunghyun
    • Applied Chemistry for Engineering
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    • v.29 no.1
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    • pp.10-17
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    • 2018
  • POU (point of use) scrubbers were applied for the treatment of waste gases including PFCs (perfluorocompounds) exhausted from the CVD (chemical vapor deposition), etching, and cleaning processes of semiconductor and display manufacturing plant. The GWP (global warming potential) and atmosphere lifetime of PFCs are known to be a few thousands higher than that of $CO_2$, and extremely high temperature more than 3,000 K is required to thermally decompose PFCs. Therefore, POU gas scrubbers based on the thermal plasma technology were developed for the effective control of PFCs and industrial application of the technology. The thermal plasma technology encompasses the generation of powerful plasma via the optimization of the plasma torch, a highly stable power supply, and the matching technique between two components. In addition, the effective mixture of the high temperature plasma and waste gases was also necessary for the highly efficient abatement of PFCs. The purpose of this paper was to provide not only a useful technical information of the post-treatment process for the waste gas scrubbing but also a short perspective on R&D of POU plasma gas scrubbers.

CFD analysis for effects of the crucible geometry on melt convection and growth behavior during sapphire single crystal growth by Kyropoulos process (사파이어 단결정의 Kyropoulos 성장시 도가니 형상에 따른 유동장 및 결정성장 거동의 CFD 해석)

  • Ryu, J.H.;Lee, W.J.;Lee, Y.C.;Jo, H.H.;Park, Y.H.
    • Journal of the Korean Crystal Growth and Crystal Technology
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    • v.22 no.3
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    • pp.115-121
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    • 2012
  • Sapphire single crystals have been highlighted for epitaxial gallium nitride films in high-power laser and light emitting diode (LED) industries. Among the many crystal growth methods, the Kyropoulos process is an excellent commercial method for growing larger, high-optical-quality sapphire crystals with fewer defects. Because the properties and growth behavior of sapphire crystals are influenced largely by the temperature distribution and convection of molten sapphire during the manufacturing process, accurate predictions of the thermal fields and melt flow behavior are essential to design and optimize the Kyropoulos crystal growth process. In this study, computational fluid dynamic simulations were performed to examine the effects of the crucible geometry aspect ratio on melt convection during Kyropoulos sapphire crystal growth. The results through the evolution of various growth parameters on the temperature and velocity fields and convexity of the crystallization interface based on finite volume element simulations show that lower aspect ratio of the crucible geometry can be helpful for the quality of sapphire single crystal.

How Do Firms' Innovation Behaviors Affect their Outputs in Korea? (기업의 혁신 활동이 기업성과에 미치는 영향)

  • Park, Jae-Min;Lee, Jung-Mann
    • The Journal of the Korea Contents Association
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    • v.11 no.3
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    • pp.339-350
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    • 2011
  • This study empirically investigates applicable possibility of open technology innovation with which the government is concerned, by figuring out the relationship between firms' innovation behaviors and innovation outputs and their utilization of information network. Empirical methodology was employed as logit regression to explain firms' innovation behaviors and the data set includes more than 2500 firms in the manufacturing sectors. First, empirical findings showed that firms' innovation competencies and behaviors can be explained as the trend of patent application, sales and innovation outputs significantly. The patents of small and medium-sized businesses are inclined to be positive to information sources of university and government-supported research institute and the sales increased when they had labs to concentrate on R&D. On the other hand, the existence of labor union turn out to be negative to their sales. Second, the types of information network which firms utilize turned out to be connected with their innovation behaviors and purposes. Third, four types of innovation, i.e., product, process, organization, and marketing innovation was employed and innovation behaviors and outputs are well connected.

Domestic Gas Turbine Industry Development Strategies Based on Domestic Supply Chain and Potential Analysis (공급사슬 및 내재역량 분석을 통해 고찰한 국내 가스터빈 산업 국산화 개발 전략)

  • Hyun, Jungwoo;Lee, Sangkyun;Jin, Hwan Jun;Park, Chinho
    • Journal of Energy Engineering
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    • v.29 no.1
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    • pp.13-24
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    • 2020
  • Many countries are actively engaging in the reduction of greenhouse gas emissions, and as part of this effort, gradually reducing the portion of coal power generation and instead increasing the portion of power generations from renewable energy sources and natural gas. Korea is taking a similar policy to expand LNG power generation for the next decade. There is a concern, though, about the policy not being aligned with the domestic industry development, since only a few products are being made in Korea along the LNG power generation industry value chain. Therefore in this paper, we first looked at the current status of the gas turbine and high temperature parts industry used for LNG power generation in Korea, and then looked into the industrial issues and challenges through the analysis of supply chains of the domestic gas turbine industry. Finally, we tried to propose strategies to revitalize and localize the domestic gas turbine and high temperature parts industry. The proposed strategies can be summarized as 1) creation of domestic gas turbine manufacturing ecosystem via construction of gas turbine alliance, 2) strategic R&D support for localization of gas turbine and high temperature parts, and 3) provision of domestic testbeds for technology evaluation and commercialization.

Development and Commercialization of Artificial Reefs from Waste Mulch Plastic Films (농업용(農業用) 멀칭 폐(廢)비닐로부터 인공어초(人工魚礁) 개발(開發) 및 상용화(商用化))

  • Kim, Hea-Tae;Shon, Sang-Jin;Kim, Myoung-Ho;Choi, Mi-Ran;Baek, Wook-Jin
    • Resources Recycling
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    • v.16 no.5
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    • pp.19-24
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    • 2007
  • Reefs are the marine structure that can give resting, inhabiting, feeding and nursing spaces for a variety of fishes. Usually artificial reefs are made of cement and steels respectively in Japan as well as in Korea. However since resources deficiency has been getting serious, other materials are taken into consideration for the basic bodies of artificial reefs. About 300 thousand tons of waste agricultural plastic films are generated every yew in Korea, but no effective recycling techniques have been developed. In this sense, artificial reefs made of waste agricultural plastic films are the most representative symbol of the recycled products in the Resource Recycling Era. In particular, since these reefs could be made of the semi-cleaned waste agricultural plastic films that still contain high portion of soil, it is very environmentally friendly not only in manufacturing process but also in using under water. Furthermore they have some evident advantages as follows; 1) high fish swarming effect 2) good initial attachment of the marine growths 3) extremely low corrosion to brine 4) easy adjustment of the gravity 5) economical manufacture, transportation and jettison 6) excellent safety to ecosystem caused by lower elution of toxic substances 7) good recyclable property after application and so on.

Direction toward Economic Development of Southwest Area of Jeonnam Province through Construction of Airport and Port Supporting Complex (공항만배후단지 조성을 통한 전남 서남권 경제발전방향에 관한 연구)

  • Park, Soomyung
    • Journal of Korea Port Economic Association
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    • v.29 no.3
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    • pp.39-72
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    • 2013
  • As a regional development gap between Southwest and Southeast of Jeonnam Province are becoming more serious, it is highly time to come up with measures for the balanced development of the two areas. This paper suggests construction of the Airport and Port Supporting Complex in apparent efforts to reduce the gap between the two areas and facilitate the Southwest economy. The Supporting Complex aims to constitute a triangle industrial cluster which is classified into the following three categories; 1. Traditional competitive industries 2. New growth engine industries 3. Attraction of companies u-turning from abroad such as China etc. To provide one-stop service through set-up of R&D Business Center is the heart of this triangle core. This paper had LQ and Shift&Share Analysis in an attempt to search for competitive industries among the traditional industries in Mokpo-si(city) and Muan-gun(county) of Jeonnam Province. As a result of the analysis, metal manufacturing industry and metal-working process products industry have been found competitive in the two areas. Among the new growth engine industries, this paper suggests precision instruments industry and advanced parts industry for utmost strengths of airport and port while u-turning industries from abroad include higher value-added textile industry and fashion industry. It is expected that all of above-mentioned industries for the triangle industrial cluster will contribute to laying the groundwork to develop regional economy further and create more jobs in the Southwest area of Jeonnam Province.

Quality Stability and Antioxidant Activity of Red Ginseng Stored for Long Periods (장기저장 홍삼의 품질안정성과 항산화효과)

  • Choi K.J.;Lee K.S.;Ko S.R.;Jang J.G.;Park J.D.;Kim M.W;Sung H.S
    • Proceedings of the Ginseng society Conference
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    • 1988.08a
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    • pp.99-107
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    • 1988
  • Samples of red ginseng. which had been manufactured and packaged by the Korea Monopoly Corporation. were stored at ambient temperatures $(12-28^{\circ}C)$ and humidities $(55-68\%)$ for one to nine years to examine their overall quality stability and. in particular. antioxidant activity. The approximate compositions. contents of various solvent extracts. and TLC and HPLC patterns of ginsenosides in the samples which are otherwise susceptible to oxidation. were stable as judged by the changes of the TLC and GLC patterns of the lipids and fatty acids. It was also found that polyunsaturated fatty acids such as linoleic (C18: 2) and linolenic acid (C18: 3) present in the samples had been very stable during the long storage periods. The intensity of the brown color of the red ginseng samples increased significantly with storage time. The pH of the aqueous extracts of the samples also increased slightly during storage. The coloration changes seem to indicate that extensive browning reactions had occurred during storage. The reducing powers of aqueous and ethanol extracts and antioxidant activity of ethyl acetate extracts also increased with storage time. The increase in reducing powers and antioxidant activity appeared to be directly attributable to the increased amounts of non-enzymatic browning reaction products formed progressively during the long storage periods. Therefore. it seems that those antioxidative compounds. which will be progressively formed in red ginseng through non-enzymatic browning reactions during the manufacturing process and long-term storage. will not only contribute to their overall quality stability but also have some significant relationship with their antiaging pharmacological effects.

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An Experimental Study on the Quality Properties of the Expansive for Dry-Shrinkage Compensation of the On-Dol Floor Mortar (온돌바닥 모르터의 건조수축 보상을 위한 팽창재의 품질특성에 관한 실험연구)

  • 이종열;이웅종;정성철
    • Journal of the Korea Concrete Institute
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    • v.13 no.4
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    • pp.314-320
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    • 2001
  • In this paper, the properties of an expansive agent (CaO-CaS $O_4$) for dry shrinkage compensation were investigated by a series of experimental program, which might be used at On-Dol heating system as mortar type. The expansion principle of the CaO-CaS $O_4$ was mainly verified. As a result of this study, the correlation between the content of the expansive agent and the compressive strength was obtained in the form of exponential function(Y = A $e^{-x}$), showing that as the content of expansive agent increased as the expansion performance with the compressive strength increased by only a certain amount. Also, as a results of the analysis of a correlation between the expansive performance and the chemical properties which generally accompanied a part of quality management in manufacturing the expensive cement, the expansive performance was relative to only the contents of the F-CaO among chemical properties(Blaine, +44$\mu\textrm{m}$R, F-CaO, S $O_3$,L.O.I). And it was clarified that the results were relative to the second order function, showing that if the contents of the F-CaO increased the expansive performance Increased.d.

Volatile Analysis of Commercial Korean Black Raspberry Wines (Bokbunjaju) Using Headspace Solid-phase Microextraction (Headspace Solid-phase Microextraction을 이용한 시판 복분자주의 휘발성분 분석)

  • Lee, Seung-Joo
    • Korean Journal of Food Science and Technology
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    • v.46 no.4
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    • pp.425-431
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    • 2014
  • In this study, the volatile compounds in 24 commercial Korean black raspberry wines were isolated by headspace solid-phase microextraction and analyzed by gas chromatography-mass spectrometry (GC-MS). A total of 43 volatile components, including 15 esters, 12 terpenes, 7 alcohols, 4 acids, 3 ketones, and 2 aldehydes, were identified. Ethyl esters and alcohols such as ethyl acetate, ethyl octanoate, isoamyl alcohol, and phenethyl alcohol were the most represented groups among the quantified volatiles. In particular, various terpenes such as DL-limonene, linalool, alpha-terpineol, and myrtenol were identified. The differences in volatile components among the 24 black raspberry wines and possible sample grouping were examined by applying principal component analyses to the GC-MS data sets. The first and second principal components explained 43.9% of the total variation across the samples. No apparent sample groupings were observed according to manufacturing locations. The samples KU, BH, SR, and MO showed higher overall levels in the concentrations of terpenes originating from black raspberry, while other samples such as BB and HB, showed higher in ethyl ester and alcohol contents produced by yeast fermentation, respectively.

Development of simulation method for heating line optimization of E-Mold by using commercial CAE softwares (전산모사 프로그램을 이용한 E-MOLD의 Heating Line 배치의 최적화 설계에 관한 연구)

  • Chung, Jae-Youp;Kim, Dong-Hak
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.9 no.6
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    • pp.1754-1759
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    • 2008
  • To produce plastic parts that have fine pattern through conventional injection molding, a lot of difficulties follow. Therefore, rapid heating and cooling methods are good candidates for manufacturing injection-molded parts with micro/nano patterns. In this study, we adopted the E-Mold patent technology. The mold for E-Mold technology has a separate heated core with micro heaters. It is very important to optimize the lay-out of the heaters in heated core because it influences both control and distribution of mold temperature. We developed a optimization method of heating line lay-out by using commercial softwares and compared the output with the experimental results. We used Pro-Engineer Wildfire 2.0 for the mold design, ICEMCFD for mesh generation, and FLUENT for heat transfer simulation. The simulation results showed the temperature profile from $60^{\circ}C$ to $120^{\circ}C$ or $180^{\circ}C$ during heating and cooling process which were compared with the injection molding experiments. We concluded that the simulation could well explain the experimental results. It was shown that the E-Mold optimization design for heater lay-out could be available through the simulation.