• Title/Summary/Keyword: Air Bar

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An experimental study on Influence of Permeability on corrosion of reinforced Concrete (철근콘크리트의 부식에 영향을 미치는 물질 투과성능에 관한 실험적 연구)

  • 김용로;김영덕;조봉석;장종호;권영진;김무한
    • Proceedings of the Korea Concrete Institute Conference
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    • 2003.11a
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    • pp.62-65
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    • 2003
  • In this study, to confirm corrosion of reinforced concrete affected by carbonation, chloride ion diffusion, absorption ratio, air permeability, measured carbonation velocity coefficient, chloride ion diffusion coefficient, absorption coefficient, air permeability coefficient. Corrosion velocity under environment of complex deterioration. And than compared corrosion velocity with these coefficients. As the results of this study, the correlation coefficient between chloride ion diffusion coefficients and absorption coefficient was revealed that it is very high. As well, an increase in carbonation, chloride ion diffusion also increases corrosion velocity. It showed that corrosion velocity was affected by the carbonation, chloride ion diffusion, absorption ratio, air permeability. Generally, data on the development of these coefficient made with none, organic B, organic A, inorganic B, and inorganic A is shown. It showed that coating of surface prevent steel bar from deteriorating.

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Development of rotary vane air blower for fuel cell (연료전지용 로터리 베인 공기 블로워 개발)

  • Ju, Byeong-Soo;Sim, Jae-Hwi;Seo, Sek-Ho;Oh, Si-Doek
    • Proceedings of the KSME Conference
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    • 2008.11b
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    • pp.2429-2433
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    • 2008
  • A rotary vane blower was developed as an air supply system for fuel cell application. As one way of improving the blower efficiency, a roller was adapted between vanes and cylinder housing. The performance of blower was investigated experimentally. The blower power input was about 115W to compress the air at normal atmospheric condition to 0.2 bar with the flow rate of 140 NLPM, resulting in the blower overall efficiency of 43%. After 400 hours of operation, the performance of blower was not changed. The result showed that developed blower was confirmed to be suitable for fuel cell application.

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Study on the Characteristics of Scroll type Stirling Engine Receiver for Solar Thermal Power (태양열 발전용 스크롤 방식 스터링엔진 흡수기 특성 연구)

  • Seo, Ho-Young;Kim, Jong-Kyu;Lee, Sang-Nam;Kang, Yong-Heack
    • 한국태양에너지학회:학술대회논문집
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    • 2009.11a
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    • pp.62-67
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    • 2009
  • This paper describes the characteristics of scroll type stirling engine receiver. Scroll type stirling engine operated scroll compressor and expander instead of piston. Pass dimension of the receiver was $14(W){\times}14(H)$ mm and total pass length was 5,049 mm. External dimension of the receiver was $300{\times}300mm$. The experimental facility consisted of parabolic dish concentrator, compressor to supply air, triplex air filter, and flowmeter. In this study, basic experimental conditions were set at a inlet pressure of 5 bar and volume flow rate of $25m^3/hr$. As a result, air temperature in receiver at each measuring position of point 1, 2, 3 were $241^{\circ}C$, $465^{\circ}C$, and $542^{\circ}C$ respectively at inlet pressure of 5.5 bar and volume flow rate of $24.6m^3/hr$. As DNI increasing, heat transfer coefficient of the receiver changed from $695W/m^2K$ to $827W/m^2K$. Average heat transfer coefficient of receiver in the experiment was $798W/m^2K$. In addition, receiver efficiency became about 83%.

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Experimental Investigation of Steam Condensation Heat Transfer in the Presence of Noncondensable Gas on a Vertical Tube (수직 튜브 외벽에서의 증기-비응축성 기체 응축 열전달 실험 연구)

  • Lee, Yeon-Gun;Jang, Yeong-Jun;Choi, Dong-Jae;Kim, Sin
    • Journal of Energy Engineering
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    • v.24 no.1
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    • pp.42-50
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    • 2015
  • To evaluate the heat removal capability of a condenser tube in the PCCS of an advanced nuclear power plant, a steam condensation experiment in the presence of noncondensable gas on a vertical tube is performed. The average heat transfer coefficient is measured on a vertical tube of 40 mm in O.D. and 1.0 m in length. The experiments covers the pressures of 2-4 bar, and the mass fraction of air ranges from 0.1 up to 0.7. From the experimental results, the effects of the total pressure and the concentration of air on the condensation heat transfer coefficient are investigated. The measured data are compared with the predictions by Uchida's and Tagami's correlations, and it is revealed that these models underestimate the condensation heat transfer coefficient of the steam-air mixture.

The Narrative Structure of Terayama Shūji's Sekkyōbushi Misemono Opera Shintokumaru (데라야마 슈지(寺山修司)의 '셋교부시(說敎節)에 의한 미세모노(見せ物)오페라' <신토쿠마루(身毒丸)>의 서사 구조)

  • Kang, Choon-ae
    • (The) Research of the performance art and culture
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    • no.32
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    • pp.489-524
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    • 2016
  • This study examines the birth of a genre, the $Sekky{\bar{o}}bushi$ Misemono Opera, focusing on how it accepted and modernized Katarimono $Sekky{\bar{o}}bushi$. Unlike earlier studies, it argues that Terayama was clearly different from other first-generation Angura artists, in that he rebirthed the medieval story $Sekky{\bar{o}}bushi$ as a modern Misemono Opera. Shintokumaru (1978) was directed by Terayama $Sh{\bar{u}}ji$, a member of the first generation of Japan's 1960s Angura Theatre Movement. It takes as its subject the Katarimono $Sekky{\bar{o}}bushi$ Shintokumaru, a story set to music that can be considered an example of the modern heritage of East Asian storytelling. $Sekky{\bar{o}}$ Shintokumaru is set in Tennoji, Japan. The title character Shintoku develops leprosy as a result of his stepmother's curse and is saved through his fiancee Otohime's devoted love and the spiritual power of the Bodhisattva Avalokitesvara. In this work, Terayama combined the narrative style of $Sekky{\bar{o}}bushi$ with J.A. Caesar's shamanistic rock music and gave it the subtitle 'Misemono Opera by $Sekky{\bar{o}}bushi$'. He transforms its underlying theme, the principle of goddesses and their offspring in a medieval religious world and the modori (return) instinct, into a world of mother-son-incest. Also, the pedestrian revenge scene from $Sekky{\bar{o}}bushi$ is altered to represent Shintokumaru as a drag queen, wearing his stepmother's clothes and mask, and he unites sexually with Sensaku, his stepbrother, and ends up killing him. The play follows the cause and effect structure of $Sekky{\bar{o}}bushi$. The appearance of katarite, a storyteller, propelling the narrative throughout and Dr. Yanagida Kunio is significant as an example of the modern use of self-introduction as a narrative device and chorus. Terayama $Sh{\bar{u}}ji^{\prime}s$ memories of desperate childhood, especially the absence of his father and the Aomori air raids, are depicted and deepened in structure. However, seventeen years after Terayama's death, the version of the play directed by Ninagawa Yukio-based on a revised edition by Kishida Rio, who had been Terayama's writing partner since the play's premier-is the today the better-known version. All the theatrical elements implied by Terayama's subtitle were removed, and as a result, the Rio production misses the essence of the diverse experimental theatre of Terayama's theatre company, $Tenj{\bar{o}}$ Sajiki. Shintokumaru has the narrative structure characteristic of aphorism. That is, each part of the story can stand alone, but it is possible to combine all the parts organically.

Effects of opening distance on liquid-gas spray of pintle injector under atmospheric condition (핀틀 인젝터의 개도가 액체-기체 상압 분무에 미치는 영향)

  • Yu, Kijeong;Son, Min;Koo, Jaye
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.43 no.7
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    • pp.585-592
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    • 2015
  • Effects of opening distance on liquid-gas spray of pintle injector were experimentally investigated under atmospheric condition by using water and air as simulants of propellants. Discharge coefficients($C_d$) and mass flow rates were calculated with various injection conditions; 0.1 bar - 1.0 bar for water pressures and 0.2 mm - 1.0 mm for the pintle opening distances. Spray angles were measured from the spray images that were obtained by a shadowgraphy method. When opening distance is 0.2 mm, liquid sheet is not formed properly and it show non-uniform spray. than it can result in combustion instability. it has a weak correlation between the momentum flux ratio and the spray angle, while it has a strong correlation between the momentum ratio and spray angle. Finally the spray angles reduced exponentially when the momentum ratio increased and the spray angles converged to about 40 degrees.

Characteristics Diagnosis of Supersonic Air Plasma by 0.4 MW Class Segmented Type Arc Torch (0.4 MW급 분절형 아크 토치에 의한 초음속 공기 플라즈마의 특성 진단)

  • Kim, Min-Ho;Lee, Mi-Yeon;Choe, Chae-Hong;Kim, Jeong-Su;Seo, Jun-Ho;Hong, Bong-Geun
    • Proceedings of the Korean Vacuum Society Conference
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    • 2013.02a
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    • pp.194-195
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    • 2013
  • 초음속 공기 플라즈마 환경을 모사할 수 있는 0.4 MW급 Enhanced Huels형 초음속 공기 플라즈마 발생 장비가 2012년에 전북대학교에 설치 완료되었다. 초음속 공기 플라즈마 시험장비는 대기권으로 reentry 할 수 있는 비행체의 열차폐체 시험평가를 주목적으로 개발되었으며, 핵융합장치용 고온 내열체 소재개발에도 활용될 예정이다. 분절형 아크 플라즈마 토치는 전극부식에 의한 오염도를 적으면서 고출력의 안정적인 플라즈마를 발생시키며, 일반적인 직류 토치로는 얻을 수 없는 초고엔탈피 플라즈마 열유동을 얻을 수 있는 특징이 있다. 구축된 장비는 최대 직류 출력 1,200 kW의 DC 전원공급장치, 0.4 MW급의 분절형 아크 플라즈마 토치, ${\phi}1.5m{\times}2m$ 크기의 진공쳄버, 1 MW의 냉각 능력을 갖춘 디퓨저와 열교환기, 진공 용량 $100m^3$/min의 진공펌프 9대, 88 g/s의 공기유량에서 NOx를 50,000 ppm에서 100 ppm으로 저감할 수 있는 후처리 시스템, 4 bar 15 g/s의 공기를 공급할 수 있는 가스 공급장치, 30 bar 600 lpm의 저전도수와 4 bar 560 lpm의 일반수를 공급할 수 있는 냉각수 공급장치로 구성되어 있다. 초음속 공기 플라즈마의 발생 특성을 시험하기 위해 플라즈마 발생 조건으로 토치공급전력 350 kW와 410 kW, 토치 공기 공급 유량 16.3 g/s, 토치 내부압력 3.9~4.2 bar, 챔버압력 40 mbar으로 시험을 수행하였다. 발생된 플라즈마 상태를 진단하기 위해 속도는 쇄기 탐침기, 열유속은 Gardon 게이지, 엔탈피와 토치 효율은 토치의 공급전력과 냉각수에 의한 손실 전력으로 각각 측정하였다.

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Development of Miniaturized High-Speed Air Spindle for Micro-Meso Components (미세부품가공을 위한 소형 초고속에어스펀들 개발)

  • Lee, Seung-Jun;Shin, In-Dong;Cha, Sao-Chang;Kim, Yong-Woo;Lee, Jong-Ryul;Lee, Deug-Woo
    • Journal of the Korean Society of Manufacturing Technology Engineers
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    • v.19 no.3
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    • pp.334-339
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    • 2010
  • The development of high-speed spindle have been studied extensively for micro machining in advanced industrial countries. The research of miniaturized high-speed air spindle is important part which needs for the micro machining process of high quality. So, This study was to carry out results about design characteristics of miniaturized high-speed air spindle. We had designed 4type turbines and shaft. They were simulated in use the computer simulation programs. We made them as products. They measured RPM (revolutions per minute). As a result of experiments, there was a contrast among 4type Turbines. it reached 384,000rpm in 4.5bar of air pressure. And, We tried to compare the results of measurement whit the results of computer simulation.

An Experimental Study on the Cooling Effect by a Turbulence Promoter in Impinging Air Jet System (충돌분류계(衝突噴流系)에서 난류촉진체(亂流促進體)에 의한 방열효과(放熱效果)에 관(關)한 연구(硏究))

  • Lee, Y.H.;Seo, J.Y.
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.4 no.1
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    • pp.48-56
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    • 1992
  • The purpose of this study was to investigate the enhancement of heat transfer without additional external power in the case of rectangular air jet impinging vertically on the flat heating surface. In an attempt to enhance the heat transfer rate in two-dimensional impinging jet, the technique used in the present study was placement of square rod bundles as a turbluence promoter in front of the heat transfer surface. The effects of the clearance between the flat plate and square rod, and the nozzle exit velocity on the heat transfer characteristics have been investigated experimentally. The results obtained through this study were summerized as follows. High heat transfer enhancement was achived by means of flow acceleration and thinning of boundary layer by inserting rods in front of the heating flat plate. The smaller the clearance between rod and heating plate was, the larger heat transfer effect became. Average Nusselt number reached maximum at $Re=5.76{\times}10^4$ and C=1㎜ and the enhancement rate of heat transfer became maxium at this condition with the enhancement ratio as high as about 1.427 when normalized by the flat plate value. The correlating equation of average Nusselt number and Reynolds number was obtained, which is $\bar{N}uo=1.324{\cdot}Re^{0.459}{\cdot}(C/A)^{-0.034}$.

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Forecasting of Various Air Pollutant Parameters in Bangalore Using Naïve Bayesian

  • Shivkumar M;Sudhindra K R;Pranesha T S;Chate D M;Beig G
    • International Journal of Computer Science & Network Security
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    • v.24 no.3
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    • pp.196-200
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    • 2024
  • Weather forecasting is considered to be of utmost important among various important sectors such as flood management and hydro-electricity generation. Although there are various numerical methods for weather forecasting but majority of them are reported to be Mechanistic computationally demanding due to their complexities. Therefore, it is necessary to develop and build models for accurately predicting the weather conditions which are faster as well as efficient in comparison to the prevalent meteorological models. The study has been undertaken to forecast various atmospheric parameters in the city of Bangalore using Naïve Bayes algorithms. The individual parameters analyzed in the study consisted of wind speed (WS), wind direction (WD), relative humidity (RH), solar radiation (SR), black carbon (BC), radiative forcing (RF), air temperature (AT), bar pressure (BP), PM10 and PM2.5 of the Bangalore city collected from Air Quality Monitoring Station for a period of 5 years from January 2015 to May 2019. The study concluded that Naive Bayes is an easy and efficient classifier that is centered on Bayes theorem, is quite efficient in forecasting the various air pollution parameters of the city of Bangalore.