• Title/Summary/Keyword: Manometer

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The Effects of the Arc Pressure Variation on the Penetration by the filler Wire Feed Rate in Pulsed TIG Welding (펄스 TIG용접에서 필러 와이어 송급속도에 따른 아크압력 변동이 용입에 미치는 영향)

  • 조상명;김진우
    • Journal of Welding and Joining
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    • v.22 no.1
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    • pp.71-76
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    • 2004
  • In the standpoint of the arc pressure, the effects of the filler wire feed rate on the penetration was investigated in this study. The pure Ar gas was used as a shield gas and the parameters investigated were the welding current and the filler wire feed rate. By making the experiment on the arc pressure, we could know that the arc pressure was fluctuated as the depth-into-arc of the tungsten rod. Instead of the filler wire, the tungsten rod was supplied into the molten pool to make this experiment. Because the filler wire melted in arc and then we couldn't measure the arc pressure. So, the tungsten rod - the highest melting point - was used. According to the depth-into-arc of the tungsten rod, the arc pressure could be measured by using the manometer. It was proved that the arc pressure got higher as the wire feed rate was slow. It is reported the arc pressure is proportion to welding voltage and the square of welding current. But, in the filler wire TIG welding, we could blow that arc pressure was fluctuated as the depth-into-arc of filler wire was changed. We could measure the arc pressure by the variation of the filler wire feed rate and could verify that it affected bead shape and penetration.

Establishment of Low Vacuum Standard in the 1 to $1~10^5$ Pa Range ($1~10^5$ Pa 영역의 저진공 표준 확립)

  • 홍승수;신용현;정광화
    • Journal of the Korean Vacuum Society
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    • v.5 no.3
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    • pp.181-187
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    • 1996
  • The Ultrasonic Interferometer Manometer(UIM) which can calibrae from1 Pa to $10^5$Pa has been developed, and its uncertainty is evaluated less than $\pm$(30ppm of pressure+12mPa). We can calibrate Capacitance Diaphragm Gauge(DCG) used as a transfer standard gauge in the low vacuum field. TheUIM enables to maintain the measurement traceability for industries. In order to improve the UIM's accracy, we will perform the international intercomparison withother national standards laboratories.

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The Effect of Surface Area Implant on Bonding Strength between Implant and Bone (임프란트의 외표면적이 임프란트와 골과의 결합력에 미치는 영향)

  • Jo, Seong-Am
    • Korean Journal of Materials Research
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    • v.8 no.7
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    • pp.613-615
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    • 1998
  • 임프란트의 외표면적이 골과의 결합의 정도에 미치는 영향을 알아보기 위하여 10개의 grade ll 티타늄 임프란트를 사용하여 이를 직경 3미리와 5미리의 2개의 군으로 나누어 10마리의 토끼의 무릅뼈에 삽입하였다. 6주후에 동물들을 희생시키고 회전제거력을 Tohnichi 15-BTG-N Torque garge Manometer로 측정하여 5nmwlrrud 그룹의 회전제거력이 3mm직경 그룹의 회전제거력보다 큰 것을 확인하였다. (p=0.008)

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Numerical and experimental study of the flow characteristics around two vertical cylinders (2개의 수직실린더 주위 유동 특성 연구)

  • Shin Young-S.;Jo Chul-H.;Jeong Uh-C.
    • Proceedings of the KSME Conference
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    • 2002.08a
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    • pp.213-216
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    • 2002
  • In this paper, flow patterns around two vertical cylinders were investigated numerically and experimentally Flow patterns between cylinders are very complex and interative. Changing gaps between cylinders the flow patterns are measured and numerically studied at a fixed comming velocity. The experiment has beeen conducted in circulating water channel with PIV system and manometer, and numerical analysis has been made by F.D.M. and multi block method. The results can be applied in the understanding and design of multiple pile array structures.

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The accuracy of electric manometer measuring vital signs (정확한 전자 Vital Sign 측정기)

  • Lee Eun Ok
    • The Korean Nurse
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    • v.4 no.3 s.17
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    • pp.46-52
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    • 1965
  • 전자신체기능 측정기가 발명되어 현재 그 자동장치의 효능에 대해서 전국 각지에서 조사하고 있다. 그리하여 전자측정기에 의한 vital sign측정이 종례의 방법보다 좋은 점이 있다는 사실을 지금 바야흐로 발견하기 시작하고 있다. 간호원은 종래의 측정방법에 변화성과 오류가 있을 수 있고 두 가지 중 어느 방법을 택하더라도 정상범위 안에서의 변화나 개인차는 있다는 것을 이해하지 않으면 안 된다고 생각한다. 여기에서 가장 강조하고 싶은 것은 vital sign에 어떤 변화가 생겼을 때 그 변화를 현명하게 해석해서 그의 중요성 여하를 평가할 수 있는 간호원이 되어야 한다는 것이다.

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Study on The Water Requirements of Chinese Cabbage. (배추 용수량에 관한 연구)

  • 김현철;정두호
    • Magazine of the Korean Society of Agricultural Engineers
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    • v.16 no.2
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    • pp.3430-3437
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    • 1974
  • .It is very importaut to know the water consumption of crops in planning irrigation works and practicing suitable soil moisture management. For the purpose of making it clear that how much water be consumed to cultivate the Chinese cabbage, Chamber method has been applied. Main equipments in the transpiration chamber are flowers, manometer and electric thermograph. The chamber made of vynyl plate has a small entrance at the base and an exit at the top, and the ventilation in the chamber was carried out by a flower through the entrance and exit. Air-flow adjusted by an orifice manometer enters the chamber from the outside over the crop canopy through the pipe like a chimney and finally goes out to the outside. Two sets which consist of a pair of dry and wet bulb made by thermistor are installed in the entrance and exit tube, and record air temperature automatically. Evapotranspiration amount is computed from the air-flow quantity and difference in absolute humidity between at the entrance and exit of the chamber by the following equation: ET=(X2-X1)${\times}$Q where ET=evapotranspiration amount X1=absolute humidity at the entrance(g/㎥) X2=absolute humidity at the exit(g/㎥) Q=air-flow quantity(㎥) This study was carried out at the upland farm of the Institute of Agriculture Engimeering and Utilization, Suwon, Korea. from 1971 to 1973. The results obtained in this experiment are as follows: 1. The total amount of evapotranspiration of Chinese Cabbage that is cultivated in autumn is 408.1mm during growth period. 2. Chinese cabbage rapidly grows up in the second ten days of September, 40th to 50th days after seeding. At the same time, the maximum amount of evaportranspiration of Chinese cabbage is 61.6mm/10 days 3. The correlation between Pan-evaporation and evapotranspiration is high, coefficient of correlation r=0.88**, and can be shown as The following regression equation: ET=0.913E+20.273 4. Evapotranspiration is closely related with meteorological factors: r=0.85**, for insolation, r=0.76** for air temperature, respectively. 5. The percentage of evapotranspiration amount, at the beginning of growth stage, gradually increases in proportion as the Chinese Cabbage grows but is largely affected by meteorological factors after the green cover formation. 6. By Blaney and Griddle formula, evaportranspiration coefficient "K" are within from 0,85 to 1.27.

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A Study of Swirling Flow in a Cylindrical Tube Port 1, Velocity Profiles (수평 원통관내에서 Swirling Flow의 유동에 관한 연구(I))

  • Medwell, J.O.;Chang, T.H.;Kwon, S.S.
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.1 no.4
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    • pp.265-275
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    • 1989
  • An experimental study of decaying swirl air flow has been obtained by tangential inlet in a straight tube with Reynolds number range 20,000~40,000. The friction factor, swirl angle, velocity profiles and turbulent intensity are measured by using micro-manometer and hot-wire anemometer. It is found that the swirl flow behaviors depend on the swirl intensity along the test tube.

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Stall and Counter-measure for Large Size Axial-Flow Fan (대형축류팬의 실속과 대책)

  • Shim, Eui-Bo
    • 유체기계공업학회:학술대회논문집
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    • 1998.12a
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    • pp.70-77
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    • 1998
  • The rise in pressure across the impeller blade of an axial flow fan depends on the angle of attack. At a low back pressure, the air volume will be large and the angle of attack is small. The gradual increase of the back pressure approached stall zone which is not stationary but travels blade to blade passage. In consequence, a region occurs around these blades with large vibration in the flow. To avoid these stall operation, the stall detector in the axial flow fans has been designed to detect stalling condition with a manometer or differential pressure switch by electric mechanism.

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RESISTANCE OF COFFEE BEANS AND COFFEE CHERRIES TO AIR FLOW

  • Nordin Irbrahim, M.
    • Proceedings of the Korean Society for Agricultural Machinery Conference
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    • 1993.10a
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    • pp.886-895
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    • 1993
  • Experimental were conducted to obtain information on the effect of airflow rates and bed depths on the resistance of coffee cherries and coffee beans available locally (Coffea Liberica). The airflow used were in the range of 0.06 to 0.6 cu. m/s-sq.m. The moisture content of the coffee cherries ranged from 10 % to 50% (wet basis) and that of coffee beans ranged from 12% to 30% )wet basis). Two methods of filling were used i.e. loose fill and packed fill. Pressure drops across the material bed in a vertical column were measured at several depths using inclined manometer. The pressure drop increased directly with air flow rate as well as bed depths. The effects of air flowrates and moisture contents on the resistance in terms of pressure drip per unit bed depth were analysed. The pressure drop per unit depth across the material bed varied slightly due to different depth. The resistance to airflow decreased with the increase in moisture content for loose fill. However, the effect of moisture content is not apparent for packed fill.

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A Study for the Pressure Drop of Static Mixers (스태틱 믹서의 압력손실에 대한 연구)

  • 양희천;박상규
    • Journal of Advanced Marine Engineering and Technology
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    • v.27 no.2
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    • pp.299-304
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    • 2003
  • Static mixer consists of a straight pipe of circular cross section into which individual elements are inserted to cut, fold, twist and re-combine the mixing fluid. The number of elements and their shape required in any application depend on the complexity of the mixing process. The objectives of this study are to develop a new static mixer and to perform the experimental investigation of pressure drop in order to evaluate the performance of the new one. The mixing fluid used is Glycerin. The pressure drop is measured using a hydraulic manometer and the correlation of Z-factor is suggested as a function of Re. The Z-factors of SSC and YNU mixer are about 40% lower than and 4% higher than that of the Sulzer one.