• Title/Summary/Keyword: Nip point

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Determination of the process variables for quality monitoring in direct rolling processes (직접압연 공정에서 품질계측을 위한 공정변수의 선정)

  • 배세철;박영준;조형석
    • 제어로봇시스템학회:학술대회논문집
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    • 1996.10b
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    • pp.1364-1367
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    • 1996
  • Recently, direct rolling process, called as strip casting process, has been interested in to save production cost by reducing forming processes. In direct rolling process, since a steel strip of thickness 1-5(mm) can be produced directly from molten metal, it can eliminate secondary hot rolling process. On the other hand, since many process variables are existed in this process and relation of these variables is very complex, it is difficult to realize the process design and the quality control. In this paper, as first step to overcome above difficulties, the quantitative relationship of the process variables affected to quality of the strip has been carried out through the numerical analysis. Also, we determined the process variable to monitor the quality in the direct rolling process. As a result, we show that the solidification final point, called as Nip point, was related directly to quality of the strip.

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Computer Simulation for the Cavitation Changes at the Exit of Offset Printing Nip (오프셋 인쇄의 틈새출구에서 공동의 변화에 대한 시뮬레이션)

  • Youn, Jong-Tae;Kim, Yun-Taek;Lim, Soo-Man
    • Journal of Korea Technical Association of The Pulp and Paper Industry
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    • v.46 no.3
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    • pp.1-10
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    • 2014
  • Offset paper printing is a promising roll-to-roll technique for color printed materials. Although it is no doubt that understanding ink transfer mechanism in offset printing process is necessary to achieve high printing quality, investing the relationship between inks and substrates at the nip is difficult experimentally due to high printing speed. In this paper, rheological behavior and splitting point of the ink at the nip is studied using package software Ployflow and Flow 3D based on Navier-Stokes equation. Polydimethylsiloxane (PDMS) ink and IGT printability tester were used for an model ink and experiment to compare with that of simulation data, respectively. As a result, higher viscosity at state flow and pressure increased ink transfer due to higher possibility of presence of cavitation at the nip and increase in covering area ratio. These results have shown good agreements with experimental data compared by measuring density of print through.

Current Status of Human Papillomavirus Infection and Introduction of Vaccination to the National Immunization Program in Korea: an Overview

  • Kim, Min-A;Han, Gwan Hee;Kim, Jae-Hoon;Seo, Kyung
    • Journal of Korean Medical Science
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    • v.33 no.52
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    • pp.331.1-331.17
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    • 2018
  • Human Papillomavirus (HPV) infection is the most common sexually transmitted infection and is associated with the development of cervical cancer. The purpose of this report is to provide the literature evidences on selecting the HPV vaccine for national immunization program (NIP) in Korea. To complete these tasks, we reviewed domestic and foreign literature on the current status of HPV infection, efficacy and effectiveness of HPV vaccine, safety of vaccine and cost effectiveness analysis of vaccination business. Given that the median age of first sexual intercourse is continuing to fall, this may have serious implications for HPV infection and cervical cancer incidence at the age of 20s. The World Health Organization recommends that the HPV vaccination should be included in the NIP being implemented in each country. Both the bivalent and quadrivalent vaccines have a 90% or greater preventive efficacy on cervical intraepithelial lesion 2-3 and cervical cancer by the HPV 16 or HPV 18. In the future, if HPV vaccination rate as part of NIP increases, it is expected that the incidence of HPV infection, genital warts, and cervical precancerous lesions will be decreased in the vaccination age group. Therefore, in order to increase the HPV vaccination rate at this point in Korea, social consensus and efforts such as the introduction and promotion of HPV vaccine to the NIP according to appropriate cost-effectiveness analysis are required.

The Splitting Point of Liquid Film between two Rotating Rollers (두 회전 롤러 사이의 유체 Splitting Point에 관한 연구)

  • Lim, Kyu-Jin;Shin, Joong-Soon
    • Journal of the Korean Graphic Arts Communication Society
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    • v.23 no.2
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    • pp.129-141
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    • 2005
  • The liquid film behavior between two rotating rollers has been analyzed for many years. Their contributions were, however, limited almost within the areas of polymer laminar flow in there. When the slip contact of two rotating rollers is used as a role of vehicle to distribute the liquid discharged on to each roller after splitting from the nip, there was few available relationship to control the roller speed and to design system. On this work it was possible to get out a certain relationship between the discharged film thickness ratio and the roller surface seeds without any help of pressure limit at the splitting point. The hydrodynamic analyzation of Newtonian liquid behavior around the point was well proved on some manipulative experiment. The thickness ratio increases along with the roll surface speed ratio increases. And the discharged volume flow rate ratio on each roller surface varies with square of the speed ratio. Both of these relationship have a decision factor also made up by the speed ratio.

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A Study on Property of Thermoset Composite in FPS Process (FPS 공정에 의한 열경화성 복합재 유효성 검증 연구)

  • Kim J-H;Um M-K;Byun J-H;Lee S-K;Jeon Y-J
    • Proceedings of the Korean Society For Composite Materials Conference
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    • 2004.10a
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    • pp.241-245
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    • 2004
  • Among the various manufacturing processes of composites, the tape lay-up process of thermoset prepreg has many advantages compared to autoclave or hot press forming. It has a high potential to process automation and continuous fabrication .. Fiber placement developed as a logical combination of filament winding and automated tape placement to overcome some of the limitations of each manufacturing method. Fiber placement uses a compaction device to apply direct contact between the incoming materials in the fiber placement head and Heat is added to the materials at the nip point of the compaction roller. This paper will discuss property of thermoset composite as compaction and heat effect in Automated fiber placement

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Polyester Film Laminating Technology for Chip Condenser

  • Lee, Yun Dai;Son, Yang Soo;Ahn, Joong Geol
    • Corrosion Science and Technology
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    • v.3 no.4
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    • pp.172-177
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    • 2004
  • Biaxially oriented polyethylene terephthalate copolymer(BO - PET)film laminated aluminiums have been applied for chip condenser case. The BO PET film is characterized by high molecular which gives high corrosion resistance, good adhesion and high heat resistance. The higher orientation lowers formability of the film. So, optimum orientation has to be controlled during the laminating process. And to confirm the adhesion between BO PET and aluminium and to guarantee the formability of PET laminated aluminums, we have controlled the chromium oxides weight on the aluminium and laminating condition ( laminating temperature, soaking temperature and lag time after nip roll and quenching conditions) This paper discusses the effect of the laminating conditions on the formability of laminated aluminums. As results, it is clear that the orientation of the BO PET film decreased with an increase in the strip temperature. When the film temperature is over the melting point of the film, its orientation drastically decreased.

Research for Health Examinations for Infants and Children by Korean Medicine (한방 영유아 건강검진 도입 필요성 연구)

  • Yu, Seung Ju;Cheon, Jin Hong;Kim, Ki Bong
    • The Journal of Pediatrics of Korean Medicine
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    • v.30 no.2
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    • pp.10-22
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    • 2016
  • Objectives This study is to analyze current guidelines for health check-ups in infants and children, and to develop better guidelines based on oriental medicine. Methods We analyzed The Manual of 2015's Health Examination for Infants and Children which is a Korean Developmental Screening Test for Infants and Children (K-DST). The statistics from the test was collected from 2010 to 2014 to figure out the problems of Health Examinations for Infants and Children. 20 articles from 2000 to 2014 from RISS, NDSL were also analyzed. Results The current guidelines for health examinations in infants and children didn't include major pediatric diseases such as allergy and asthma. Also, the pediatrics health education materials were mainly focused on hypernutrition but not so much on nutrition deficiency. The number of the centers for Health Examinations for Infants and Children was 52.2% of the number of NIP-Participating medical institutions for infants and children. Conclusions Oriental medicine can be useful to prevent major pediatric diseases and to promote general health in pediatrics. By legislating 'Geon-a-beop', which is a law for infants and children, we can increase the number of medical centers for infants and children to get health check-ups. Currently, there are 9,769 Korean medical institutions, and the rate of traditional medical doctors of public health doctors was 25.5%. Weak Children Questionnaire is developed, considered to be more useful when it is developed with 5-point scale rather than 2.