• Title, Summary, Keyword: 삼각막대형

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A Study on Flow Characteristics of a Separate Triangular Bar Differential Pressure Flow Meter for Measuring Exhaust Flow Rate of Diesel Engine (디젤엔진 배기 가스 유량 측정용 삼각 분리 막대형 차압유량계 유량 특성 연구)

  • Lee, Choong-Hoon;Kim, Kwang-Il;Kim, Min-Chang;Park, Dong-Sun
    • Journal of the Korean Society for Railway
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    • v.10 no.5
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    • pp.563-568
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    • 2007
  • A separate triangular bar type differential pressure flow meter was developed for measuring exhaust gas flow rate from Diesel engine. Three kinds of the separate triangular bar flow meters whose aerodynamic angles are different one another are made and evaluated, respectively. The experimental results show that an aerodynamic shape has a effect on the pressure difference between upstream and downstream at the flow meter, that is, the thinner the shape of the separate triangular bar flow meter is, the smaller the pressure difference at the flow meter is. The separate triangular bar type flow meter was calibrated at both cold and high temperature of the gas flow. A burner system was designed for raising the gas temperature and it was well operated in controlling the gas temperature. An empirical correlation between mass flow rate and differential pressure at the separate triangular bar flow meter was obtained and the empirical correlation was also corrected by the gas temperature.

Effects of Pressure Tapping on flow Rate Characteristics of Triangular Separate Bar Differential Pressure flow Meter (삼각 분리 막대형 차압 유량계의 압력탭이 유량 특성에 미치는 영향)

  • Lee, Choong-Hoon;Park, Dong-Sun
    • Proceedings of the KSR Conference
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    • pp.1680-1686
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    • 2009
  • Flow characteristics of a differential pressure flow meters which have a shape of triangular separate bar (TSB) was investigated according to machining conditions in pressure tapping holes. Size of pressure tapping holes is machined with either 1.0 mm or 1.5 mm in diameter. Also, number of pressure tapping holes are drilled either 9 or 17. The mass flow rate of the TSB flow meters are calibrated with a laminar flow meter by connecting them in line. The mass flow rate in the TSB flow meters are plotted with a non-dimensional parameter H which includes the gas temperature, exhaust gas pressure and differential pressure at the flow meters, and atmospheric pressure. An empirical correlation between the mass flow rate at the TSB flow meter and the non-dimensional parameter H was obtained. The empirical correlation showed highly linear relationship between the mass flow rate and the non-dimensional parameter H. The hole size of the pressure tapping holes has a bigger effect on the flow rate than the number of the tapping holes.

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A Study on Flow Rate Characteristics of a Triangular Separate Bar Differential Pressure Flow Meter according to the Variation of Gas Flow Temperature (유동 가스 온도 변화에 따른 삼각 분리 막대형 차압 유량계 유량 특성에 관한 연구)

  • Kim, Kwang-Il;Yoo, Won-Yuel;Lee, Choong-Hoon
    • Transactions of the Korean Society of Machine Tool Engineers
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    • v.17 no.4
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    • pp.89-94
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    • 2008
  • Differential pressure flow meters which have a shape of triangular separate bar(TSB) were tested for investigating the flow rate characteristics of the flow meters with varying the temperature of the gas flow. Three kinds of the triangular separate bar flow meters whose aerodynamic angles are different one another are used. The mass flow rate of the flow meters are evaluated using a non-dimensional parameter which includes the gas temperature, exhaust gas pressure and differential pressure at the flow meters, and atmospheric pressure. A burner system which is similar to gas turbine was used for raising the gas flow temperature. The burner system was operated with varying the air/fuel ratio by controlling both the fuel injection rate from the fuel nozzle and air flow rate from a blower. An empirical correlation between the mass flow rate at the TSB flow meter and the non-dimensional parameter was obtained. The empirical correlation showed linear relationship between the mass flow rate and the non-dimensional parameter H. Also, the mass flow rate characteristics at the TSB flow meter was affected by the gas temperature.

Design and Implementation of Single-Feed Dual-Band Circular Polarization Triangular Antenna for Reception of GPS and DMB Signals (GPS와 DMB 신호 수신을 위한 단일 급전 이중 대역 원형 편파 삼각 패치 안테나 설계 및 구현)

  • Lee, Won-Kew;Kim, Sung-Min;Yang, Woon-Gen
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.16 no.9
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    • pp.893-902
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    • 2005
  • We propose a novel single-feed triangular patch antenna with bar-type slots for dual-band circular polarization operation. And also propose a H-type slotted triangular patch antenna to enhance the ratio of the resonance frequencies. 3 cases of desist examples with bar-type slots were investigated and also 4 cases of H-slotted antennas were investigated to meet the dual-band requirement for GPS(Global Positioning System) and DMB(Digital Multimedia Broadcasting). One suitable design example was implemented and measured. Simulation results of the design example for GPS and DMB system show that axial ratio and maximum gain are 3.80 dB, 8.85 dBi for low-band at 1.575 GHz and 2.02 dB, 8.60 dBi for high-band at 2.642 GHz, respectively. Measured results of the implemented antenna show that $S_{11}$ is -12.43 dB for low-band at 1.575 GHz and less than -18.75 dB for high-band, respectively.

Effects of Pressure Tapping Conditions on Flow Rate Measurement of Triangular Separate Bar Differential Pressure Flow Meter (삼각 분리 막대형 차압유량계 압력탭 조건이 유량 측정에 미치는 영향)

  • Lee, Choong-Hoon
    • Journal of the Korean Society of Safety
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    • v.25 no.2
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    • pp.1-6
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    • 2010
  • Flow characteristics of differential pressure flow meters which have a shape of triangular separate bar (TSB) was investigated according to the machining conditions in pressure tapping holes. Diameter of the pressure taping holes is either 1.0 mm or 1.5 mm. Also, number of the pressure tapping holes are drilled either 9 or 17. The mass flow rate of the TSB flow meters are calibrated with a laminar flow meter by connecting them in line. The mass flow rate in the TSB flow meters are plotted with a non-dimensional parameter H which includes the gas temperature, exhaust gas pressure and differential pressure at the flow meters. An empirical correlation between the mass flow rate at the TSB flow meter and the non-dimensional parameter H was obtained. The empirical correlation showed highly linear relationship between the mass flow rate and the non-dimensional parameter H. The hole size of the pressure tapping holes has a bigger effect on the flow rate than the number of the tapping holes.

A Study on Flow Rate Characteristics of a $Annubar^{(R)}$ Type Differential Pressure Flow Meter with a Shape Improvement ($Annubar^{(R)}$형 차압유량계 형상 개선에 따른 유량 특성 연구)

  • Oh, Dae-San;Lee, Choong-Hoon
    • Journal of The Korean Society of Manufacturing Technology Engineers
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    • v.19 no.2
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    • pp.204-210
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    • 2010
  • The inner structure of the triangular separate bar (TSB) was improved to enhance the productivity of the TSB flow meter by simplifying the machining process for making the flow meter. The cross section of upstream and downstream pressure chamber in the TSB was changed from triangle to circle, which make it possible to substitute the wire cutting by drilling in the process of machining the pressure chamber. The flow rate characteristics of the flow meters was calibrated with a laminar flow meter. Six kinds of flow meters whose diameters of pressure tap for measuring pressure of both upsteam and downstream pressure chamber were different one another were made. The effects of the pressure tap diameter on the flow rate characteristics of the TSB flow meter was little. The mass flow rate characteristics of the flow meters with increasing a non-dimensional parameter which includes the gas temperature, exhaust gas pressure and differential pressure at the flow meters and atmospheric pressure shows nearly linear relationship with a correlation coefficient of R=0.998.

Growth Condition of Liquid Culture by Pleurotus ostreatus (액체배양에서 느타리버섯균의 적합한 생장조건 구명)

  • Sung, Jae-Mo;Moon, Hee-Woo;Park, Dong-Soo
    • The Korean Journal of Mycology
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    • v.27 no.1
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    • pp.1-9
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    • 1999
  • For the practical using of liquid spawn we carried out selection test of nutrient sources, cultural methods and cultural apparatus for liquid spawn production of oyster mushroom(ASTI 2001, ASTI 2018, ASTI 2072, ASTI 2016, ASTI 2070, ASTI 2180, ASTI 2183, ASTI 2042). The optimal temperature and pH range for mycelial growth of Pleurotus species were $25^{\circ}C\;to\;30^{\circ}C$ and 5.5 to 6.5, respectively. The effect of carbon sources, nitrogen sources and mineral salts on the mycelial growth was studied using petridish culture. Generally, the disaccharides and polysaccharides showed good effect for mycelial growth of Pleurotus species, and the polysaccharides were superior to the other classes of carbon sources for mycelial growth. For the mycelial growth of the 8 oyster mushroom stains, soybean flour was superior to the other kinds of nitrogen sources. On the other hand, addition of mineral salts did not affect, and even poor under certain mineral salts, the mycelial growth of the 8 oyster mushroom stains. The brown sugar selected out the carbon source of the agricultural medium. Also the soybean flour selected out the nitrogen source of agricultural medium. In the medium selection, we selected out agricultural optimum medium composed of brown sugar 3%, soybean flour 0.3%, potassium phosphate 0.05%, magnesium sulfate 0.05%. Under the 250 ml erlenmeyer culture, the effects of such factors as the inoculum rate, the working volume, cultural method and flask shapes on the mycelial growth were examined. The optimal inoculum rate and working volume on the mycelial growth of oyster mushroom was 2 mycelial disk (diameter 6 mm) and 100 ml, respectively. The shake flask culture was enhanced the mycelial growth than at the erlenmeyer flask. Pulp form growth of mycelium in the erlenmeyer flask culture was obtained in the culture with glass rod of length 50 mm, diameter 10 mm.

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