• Title/Summary/Keyword: Spin-Off Mechanism

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Aerosol Generation Mechanism for Cutting Fluid in Turning (선삭에서 절삭유 미립화 생성 메카니즘)

  • 박성호;고태조;김희술
    • Proceedings of the Korean Society of Machine Tool Engineers Conference
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    • 2001.10a
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    • pp.179-184
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    • 2001
  • The mechanism of the aerosol generation consists of spin-off, splash, and evaporation/condensation. Most researchers showed some theoretical model for predicting the particulate size and generation rate without cutting in turning operation. These models were based on the spin-off mechanism and verified good for modeling the process. However, in real machining, the cutting tool destructs the spin-off process, and the majority of the mist is due to splash. In this paper, we show some experimental evidence the aerosol generation mechanism should be explained with splash model as well as spin-off.

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Experimental Verification of Aerosol Generation Mechanism for Cutting Fluid in Turning (선삭에서 절삭유 미립화 생성 메카니즘의 실험적 검증)

  • 고태조;오명석;박성호;김희술
    • Journal of the Korean Society for Precision Engineering
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    • v.19 no.12
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    • pp.93-99
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    • 2002
  • The mechanism of the aerosol generation generally consists of spin-off, splash, and evaporation/condensation. Most researchers showed some theoretical model for predicting the particulate size and generation rate without real cutting in turning operation. These models were based on the spin-off mechanism, and verified good for modeling the process. However, in real machining, the cutting tool destroys the spin-off process, and the majority of the mist is due to splash. In this paper, we show some experimental evidence that the aerosol generation mechanism in real machining should be explained with splash model as well as spin-off.

A Study on the Environmentally Conscious Machining Technology Cutting Fluid Atomization and Environmental Impact through Spin-Off Mechanism in fuming Operation(1) (환경 친화적 기계가공 기술에 관한 연구 선삭가공시 회전분리기구에 의한 절삭유 미립화와 환경영향(I))

  • Hwang, Joon;Chung, Eui-Sik
    • Journal of the Korean Society for Precision Engineering
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    • v.19 no.3
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    • pp.73-79
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    • 2002
  • This paper presents the experimental results to verify the environmental consciousness with economic balances due to cutting fluid behaviors, effectiveness in machining process. Even though cutting fluid improves the Productivity through the cooling, lubricating effects, its environmental impact is also increased according to the cutting fluid usage. The primary mechanism considered in this study is the spin-off motion of fluids away from rotating workpiece. In this study some parameters arc adopted to analyze the productivity(tool wear), environmental impact(mist diffusion rate). The results present talc criteria for the resonable cutting fluid usage quantitative1y to develop the environmentally conscious machining process.

Mist Formation Characteristics in Turning (선삭 가공시의 미스트 발생 특성)

  • 오명석;고태조;박성호;김희술;정종운
    • Proceedings of the Korean Society of Machine Tool Engineers Conference
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    • 2002.10a
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    • pp.147-152
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    • 2002
  • The mechanism of the aerosol(mist) generation generally consists of spin-off, splash, and evaporation/condensation. Host researchers showed some theoretical model for predicting the particulate size and generation rate without real cutting in turning operation. These models were based on the spin-off mechanism, and verified good for modeling the process. However, in real machining, the cutting tool destroys the flow direction of the cutting fluid and generate the heat by the relative motion of between tool and workpicee, and so the mass loading of the mist is greatly increased as compared with non-cutting. In this paper, we show some experimental data that the mist formation characteristics of cutting is different from that of non-cutting.

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Analysis of Cutting Fluid Atomization and Environmental Impact through Spin-Off Mechanism in Turning Operation for Environmentally Conscious Machining (I)

  • Joon Hwang;Chung, Eui-Sik
    • International Journal of Precision Engineering and Manufacturing
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    • v.4 no.1
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    • pp.49-55
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    • 2003
  • This paper presents the experimental results to verify the environmental consciousness with economic balances due to cutting fluid behaviors and effectiveness in machining process. The cutting fluid improves the productivity through cooling, lubricating effects, however its environmental impact also increases according to the cutting fluid usage. The primary mechanism in this study is the spin-of motion of cutting fluids away from the rotating workpiece. In this study some machining parameters are adopted to analyze the productivity as well as environmental impact. This study provides the criteria for the resonable cutting fluid usage quantitatively to develop the environmentally conscious machining process.

Analysis of Cutting Fluid Atomization and Environmental Impact through Spin-Off Mechanism in Turning Operation for Environmentally Conscious Machining(II)

  • Hwang Joan;Hwang Duk-Chul;Chung Eui-Sik
    • International Journal of Precision Engineering and Manufacturing
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    • v.6 no.3
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    • pp.3-7
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    • 2005
  • This paper presents the experimental results to verify the atomization characteristics and environmental impact of cutting fluid. Even though cutting fluid improves the productivity through the cooling and lubricating effects, environmental impact due to cutting fluid usage is also increased on factory shop floor. Cutting fluid's aerosol via atomization process can generate human health risk such as lung cancer and skin diseases. Experimental results show that the generated fine aerosol of which particle size less than 10 micron appears near working zone under typical operation conditions. The aerosol concentration also exceeds NIOSH regulations. This research can be provided as a basis of environmental impact analysis for environmental consciousness.

A Study on the Environmentally Conscious Machining Technology Cutting Fluid Atomization and Environmental Impact through Spin-Off Mechanism in fuming Operation(II) (환경 친화적 기계가공 기술에 관한 연구 선삭가공시 회전분리기구에 의한 절삭유 미립화와 환경영향(II))

  • Hwnag, Joon;Chung, Eui-Sik;Hwnag, Duk-Chul
    • Journal of the Korean Society for Precision Engineering
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    • v.20 no.2
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    • pp.50-57
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    • 2003
  • This paper presents the experimental results to verify the atomization characteristics and environmental impact of cutting fluid. Even though cutting fluid improves the productivity through the cooling, Lubricating effects, environmental impact due to cutting fluid usage is also increased on factory shop floor Cutting fluid's aerosol via atomization process can be affected human health risk such as lung cancer and skin diseases. Experimental results show that the generated fine aerosol which particle size less than 10 micron appears near working tone under typical operational conditions. The aerosol concentration also exceeds NIOSH regulations. This research can be provided a basis of environmental impact analysis fur environmental consciousness.

Creating Start-ups through Technology Transfer in Science Technology Park: A Case Study of Daedeok Innopolis

  • Seo, Junseok
    • World Technopolis Review
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    • v.2 no.1
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    • pp.21-31
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    • 2013
  • The largest and oldest science and technology park in Korea, Daedeok Innopolis has 29 government research institutes and 5 universities. Every year these research organizations of Daedeok Innopolis are generating more than 7 thousands technology patents and the government tries to commercialize technologies through simple technology licensing to private companies. To facilitate the technology transfer, the new mechanism named research institute spin-offs has been exclusively granted to Daedeok Innopolis in 2006. Since then, the Innopolis Foundation has put lots of effort to activate the mechanism in order to create more commercialization of R&D results from government research institutes (GRIs). This study is undertaken to review the interactive environment of the technology transfer in Daedeok Innopolis and study the unique mechanism which enables Daedeok Innopolis to proceed technology transfer effectively and in particular, looks at the role which can be played by the Innopolis Foundation as a government agent of the policy aimed at facilitating commercialization of using technologies developed by GRIs.

Two Dimensional Transfer Modes in $CH_2$ Spin System

  • NamGoong Hyun
    • Journal of the Korean Magnetic Resonance Society
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    • v.10 no.1
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    • pp.59-73
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    • 2006
  • Spin-lattice relaxation pathway of $CH_2$ spin system by two dimensional NOESY sequence has been discussed. Two-dimensional spectra governed by dipolar relaxation mechanism were simulated in term of transfer mode, the generalization of conventionally used magnetization mode in one dimension. The transfer matrix directly related to the Redfield relaxation matrix can be constructed by the multiplet of transfer mode. The observable relaxation transfer modes causes to variation of the off-diagonal signal intensity of phase sensitive NOESY spectra from which variable spectral density can be extracted with simple group theoretical calculation. The variation of the J-coupling peak intensity as a function of the mixing time in 2-D spectra for $n-Undecane-5-^{13}C$ and Bromoacetic $2-^{13}C$ acid has been theoretically traced.

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An Analysis of Effective Factors for Defense Technology Transfer (국방기술이전 성과영향요인에 관한 연구)

  • Park, Hyun-Jin;Lee, Jeong-Dong;Jung, Kyeong-In;Lee, Chun-Ju
    • Journal of the military operations research society of Korea
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    • v.32 no.1
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    • pp.1-12
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    • 2006
  • This study investigates key factors affecting the activity of defense technology transfer through the questionnaire survey in Korea. Defense R&D investment has played an important role in promoting the commercial technology development as well as the targeted defense sector through the spin-off mechanism as shown in many countries. Recognizing the importance of effective and efficient investment in defense technology development, the advanced countries in defense technology are trying to establish optimal technology transfer mechanism to maximize the effect of the invested R&D at the national level considering the idiosyncratic features of their own countries. Because the technology transfer mechanisms are very distinct from country to country, it is natural to question "what are the determinants of the effective and efficient technology transfer in Korea?" We tested 19 potential factors and identified 11 factors that are significantly important as the determinants of technology transfer. From the empirical findings, we discuss some policy implications to promote the technology transfer.