• Title/Summary/Keyword: RDE

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The Effectiveness of the Random-dot E by the Difference of the Illumination and Test Distance (조도와 검사 거리의 차이에 의한 Random-dot E의 영향)

  • Kim, Douk-Hoon
    • Journal of Korean Ophthalmic Optics Society
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    • v.5 no.2
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    • pp.1-4
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    • 2000
  • The test of stereoacuity provides relatively accurate assessment of binocular functior. in the clinical fields. The purpose of this study was to investigate performance on the Random-dot E(RDE) stereotest under the binocular conditions by the difference of the illumination and test distance. The more light illumination increase. The more pass of RDE stereotest increase. On the other hand. On the near distance of test target. All subjects have a pass toe RDE stereatest. But On the far distance of test target. Some subjects have a pass the RDE stereatest. According to the test distance. The more far distance of test target. the less subjects have a pass the RDE stereotest. As a results, The RDE stereotest have effected the test distance and illumination.

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Inactivation of Rutin Degrading Enzymes in Buckwheat Groats by Roasting and Steaming (메밀의 조직별 루틴분해효소 활성과 종실의 가열처리에 의한 효소 활성 억제)

  • An, Sol;Lee, Chang Min;Haile, Daniel Hailegiorgis;Yun, Song Joong
    • Korean Journal of Medicinal Crop Science
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    • v.27 no.2
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    • pp.108-114
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    • 2019
  • Background: Rutin is decomposed by rutin-degrading enzymes (RDE) during the processing of buckwheat groats, resulting in a decrease in rutin content and a further increase in the bitterness of processed products. Thus, the present study aimed to examine RDE activity in groats and various tissues of domestic buckwheat varieties and to develop a method to reduce the loss of rutin during the groat processing. Methods and Results: RDE activity and isozymes patterns were determined in Tartary and common buckwheat. RDE activity, measured by quercetin production rate, was 273 and $70{\mu}g/g$ fresh weight/min in mature Tartary and common buckwheat groats, respectively. A total of six RDE isozymes were detected in mature groats of Tartary buckwheat on a non-denaturing gel. In Tartary buckwheat groats, RDE activity decreased by approximately 81 or 71% with roasting or steaming for 5 min respectively. As the roasting or steaming time increased to 30 min, RDE activity decreased by over 95%. These results indicated that RDE was inactivated in groats by roasting or steaming. When untreated Tartary buckwheat groats were kneaded with powder, RDE was activated and the quercetin production rate increased by 62%. However, when roasted groats were kneaded with powder, the quercetin production rate decreased by 93%, mainly due mainly to inactivation of RDE, as indicated by a decrease in band intensities of the six isozymes. Conclusions: These results suggested that the loss of rutin, due to RDE activity during processing, may be reduced by 71 to 100% by roasting or steaming groats for 5 to 30 min, due in large part to the inactivation of RDE isozymes.

An Experimental Study of Tri-arc Rotating Detonation Engine Using Gaseous Ethylene/Oxygen (기체 에틸렌/산소 Tri-arc 회전 데토네이션 엔진 실험연구)

  • Lee, Eun Sung;Han, Hyung-Seok;Choi, Jeong-Yeol
    • Journal of the Korean Society of Propulsion Engineers
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    • v.25 no.1
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    • pp.19-28
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    • 2021
  • In rotating detonation engine(RDE), only the detonation wave is moving around the outer wall of the combustor. Neither a mechanical part nor flow is rotating in RDE. Thus, the RDE cross section is not necessary to be circular, but arbitrary closed section is possible. A RDE of tri-arc cross section is designed and As an example of an arbitrary cross sectioned RDE, a RDE of tri-arc cross section is designed in this study, and operational and performance characteristics were examined experimentally. The rotation of the detonation wave is confirmed by dynamic pressure sensor and high-speed camera, while the characteristics of the detonation wave were investigated at the concave and convex surfaces. In the present study, the thrust level of 17.0 N to 96.0 N was obtained depending on the mass flow rate.

Research Activities on PGC Propulsion based on RDE, Part I: Basic Studies (RDE 기반 PGC 추진기관 연구 동향, Part I: 기초연구)

  • Kim, Jung-Min;Niyasdeen, Mohammed;Han, Hyung-Seok;Oh, Sejong;Choi, Jeong-Yeol
    • Journal of the Korean Society of Propulsion Engineers
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    • v.21 no.5
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    • pp.97-107
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    • 2017
  • Fluid dynamic constant volume combustion technology detonation has been paid attention as a "game-changing" technology to overcome the efficiency and performance limitation of the present constant pressure combustion systems. For the past several years, a number of experimental and CFD-based theoretical studies have been conducted for the basic operation tests of RDE's. Present paper include a comprehensive survey on the research activities on RDE and its core technologies comprehensively to provide a direction for the future RDE researches, yet unfamiliar domestically.

Research Activities on PGC Propulsion Based on RDE, Part II: Application Studies (RDE 기반 PGC 추진기관 연구 동향, Part II: 응용연구)

  • Kim, Jung-Min;Niyasdeen, Mohammed;Han, Hyung-Seok;Oh, Sejong;Choi, Jeong-Yeol
    • Journal of the Korean Society of Propulsion Engineers
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    • v.21 no.6
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    • pp.91-102
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    • 2017
  • The early basic studies on RDE has been surveyed in the previous paper. Recently active researches are carrying on for the application to the power plant and aerospace propulsion systems. Collaboration researches are going on for the application of RDE for the gas turbine, liquid rocket and combined cycle engines in many countries. Following the previous Part 1 paper, present paper is intended to provide the comprehensive survey of recent worldwide efforts on the realistic application of RDE.

Discussions on the Combustion Dynamics of RDE with Relevance to the Liquid Rocket Combustion Instability (RDE의 연소동역학 및 액체 로켓 연소 불안정과 연관성에 대한 고찰)

  • Choi, Jeong-Yeol
    • 한국연소학회:학술대회논문집
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    • 2012.11a
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    • pp.363-366
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    • 2012
  • Detonative combustion is considered as a promising combustion mechanism for improving thermodynamic efficiency of power generation systems as a PGC, as well as high-speed propulsion systems. Among the various types of detonative combustion, RDE is fascinated by many researchers because of the simplicity and continuos operation characteristics. Present paper is an introduction to the physical and operational concept of RDE with a brief history of RDE researches and recent development activities. Additional discussions will devoted to the relevance to the tangential mode instabilities in liquid rocket engines and improvement of liquid rocket performance.

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Cu Via-Filling Characteristics with Rotating-Speed Variation of the Rotating Disc Electrode for Chip-stack-package Applications (칩 스택 패키지에 적용을 위한 Rotating Disc Electrode의 회전속도에 따른 Cu Via Filling 특성 분석)

  • Lee, Kwang-Yong;Oh, Tae-Sung
    • Journal of the Microelectronics and Packaging Society
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    • v.14 no.3
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    • pp.65-71
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    • 2007
  • For chip-stack package applications, Cu filling characteristics into trench vias of $75{\sim}10\;{\mu}m$ width and 3 mm length were investigated with variations of the electroplating current density and the speed of a rotating disc electrode (RDE). Cu filling characteristics into trench vias were improved with increasing the RDE speed. There was a Nernst relationship between half width of trench vias of Cu filling ratio higher than 95% and the minimum RDE speed, and the half width of trenches with 95% Cu filling ratio was linearly proportional to the reciprocal of root of the minimum RED speed.

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Development of Korean RDE Routes for On-road Emissions Measurement of Light Duty Vehicles (소형자동차 실제도로 주행 배출가스 측정을 위한 국내 주행경로 개발)

  • Kang, Gunwoo;Lee, Jongtae;Park, Junhong;Cha, Junepyo;Chon, Mun Soo
    • Transactions of the Korean Society of Automotive Engineers
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    • v.25 no.3
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    • pp.287-296
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    • 2017
  • Although emission regulations have been gradually strengthened in the past decade, the road transport section remains the most important source of NOx emission in air pollution. One reason is that there has been an increase in the proportion of diesel vehicles and in the volume of traffic. In addition, the certification procedure for standard emission limit does not sufficiently reflect real traffic condition and various driving patterns. Therefore, the European Commission(EC) has recently come up with the RDE-LDV(Real driving emissions-light duty vehicle) regulations, and the Ministry of Environment in Korea has been conducting research on evaluating RDE-LDV with PEMS(Portable Emission Measurement Systems). According to the trip requirements of the 2nd RDE package announced by the EC, the objectives of the present study include the development of Korean RDE routes to reflect domestic traffic and road conditions. Based on the results, both RDE routes are in correct compliance with RDE-LDV regulations, including trip requirements and trip dynamics. KOR-NIER Route 1, in particular, has a higher driving load in rural driving with regard to excessive gradient of elevation compared to KOR-NIER Route 2, including relatively plane rural driving.

Publication patterns in Restorative Dentistry and Endodontics

  • Chockattu, Sherin Jose;Deepak, Byathnal Suryakant
    • Restorative Dentistry and Endodontics
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    • v.44 no.3
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    • pp.34.1-34.9
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    • 2019
  • Objectives: Restorative Dentistry and Endodontics (Restor Dent Endod; RDE) is an English-language journal published by the Korean Academy of Conservative Dentistry, and it has been online since 2012 with quarterly publications. The purpose of this paper was to review and analyze the publications in this journal since its inception and over the 7-year period from 2012 to 2018. Materials and Methods: This paper assessed the number, type, and subject of articles published, as well as authorship patterns and article citations of the journal over a 7-year period. The citation indicator for the journal (h-index) was assessed using Google Scholar. Results: The number of articles per issue has remained relatively consistent in the 7 years that were analyzed. An analysis of the article types revealed various categories of review articles. Original research articles accounted for the most articles per volume. Twice as many articles per volume were on endodontic topics than on restorative subjects. Articles published in RDE have been widely cited in Synapse, Crossref, and PubMed Central. A country-wise mapping of authors' institutions revealed significant contributions from authors around the world. With an h-index of 24, RDE ranks third among journals in its specialty. The most cited articles were open lectures on statistics and research articles on recent concepts, technology, and materials. Conclusion: Over the last 7 years, RDE has served as a platform for a large number of manuscripts in the field of restorative dentistry and endodontics.

Estimating On-road NOx Emissions of Euro 6 Light-duty Diesel Vehicles (Euro6 소형 경유자동차의 실제 도로 주행 NOx 배출량 평가)

  • Park, Yeon-Jae;Park, Junhong;Lee, Jai-Young
    • Journal of ILASS-Korea
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    • v.21 no.4
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    • pp.207-213
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    • 2016
  • To protect air pollution of urban area from motor vehicles, emission limits for diesel vehicles have been dramatically lowered in short period. But recent studies have shown that on-road NOx emissions of light-duty diesel vehicles are considerably higher than the values measured with laboratory test procedures used for emission certification. To tackle with this issue, Ministry of Environment have a plan to introduce EU RDE-LDV (Real-driving Emission-Light-duty Vehicle) regulation. In this study, 4 Euro 6 diesel vehicles have been tested with the new test procedures published by EU to estimate on-road NOx emissions using PEMS (Portable Emission Measurement System). The results have shown that the requirements of EU RDE-LDV could be met in driving condition of metropolitan area for constitution of test routes and validity of test results. In analysing with Moving Averaging Window method the completeness and normality of test data were validated with the requirement. On-road NOx emissions were quite deviated as test vehicles and higher than the new limit of on-road NOx emission enforced from Sept. 2017, which means that RDE-LDV can effectively reduce NOx emission of diesel vehicles in real driving conditions of Korea.