• Title/Summary/Keyword: Vapor pressure

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Hydrothermal Syntheses of Hydrous Minerals, Brucite, Xonotlite, Talc, Tremolite, and Antigorite (수산화광물(水酸化鑛物)인 수골석(水滑石), Xonotlite, 활석(滑石), 투각섬석(透角閃石) 및 Antigorite의 열수합성(熱水合成))

  • Park, Hong Bong
    • Economic and Environmental Geology
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    • v.13 no.1
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    • pp.65-68
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    • 1980
  • Dolomite and quartz, starting materials, were mixed by the mole ratio of dolomite versus quartz with 1 : 0, 1 : 1, and 2 : 1, and of which was heated under saturated water vapor pressure of $20kg/cm^2(211.4^{\circ}C)$, $80kg/cm^2(293.6/C)$ and $120kg/cm^2(323.1^{\circ}C)$, respectively, during 20 hours. The results of the hydrothermal syntheses are as follows: 1) calcite crystals were formed at all cases of the reation 2) brucite crystals were formed when dolomite was heated under the saturated vapor pressure of $80kg/cm^2$ during 20 hours. 3) talc, tremolite, xonotlite, and antigorite were formed under saturated vapor pressure of $80kg/cm^2$ by 20 hours reaction.

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Dynamic Model of a Vertical Tube Absorber for Ammonia/water Absorption Refrigerators (암모니아/물 흡수식 냉동기의 수직원관형 흡수기의 동적 모델)

  • 문현석;정은수;김병주
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.14 no.10
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    • pp.844-853
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    • 2002
  • A dynamic model which simulates the coupled heat and mass transfer within a vertical tube absorber was developed. The liquid film is a binary mixture of two components, and both of these components are present in the vapor phase. The pressure, concentration, temperature and mass flow rate of the vapor are obtained by assuming that the pressure is uniform within an absorber. The model was applied to an absorber for an ammonia/water absorption refrigerator. The transient behaviors of the pressure, the outlet temperature and the concentration of the solution and the cooling water outlet temperature on a step change at the absorber inlet of the cooling water temperature, the vapor mass flow rate and the concentration of the solution were shown.

Performance Assessment of Refrigerant Vapor-Pressure Equations with Two Adjustable Parameters (두 개의 가변 변수가 있는 냉매 증기압 상관식의 성능 평가)

  • Park, Kyoung-Kuhn
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.24 no.2
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    • pp.129-135
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    • 2012
  • Performance of various temperature-dependent vapor-pressure equations with two adjustable parameters is assessed. These are Antoine, Miller, Zia-Thodos, Mejbri-Bellagi and other 10 equations. The equations are fitted to correlate the data from NIST Chemistry WebBook for 43 pure substance refrigerants from the critical point to the triple point. It was found that the Mejbri-Bellagi equation yields the lowest average absolute deviation of 0.37% compared with that of 0.58% of the Miller equation which is known to give better fit to experimental data than the Antoine equation(1.42%) does.

Manipulation of Microstructures of in-situ Phosphorus-Doped Poly Silicon Films deposited on Silicon Substrate Using Two Step Growth of Reduced Pressure Chemical Vapor Deposition (감압화학증착의 이단계 성장으로 실리콘 기판 위에 증착한 in-situ 인 도핑 다결정 실리콘 박막의 미세구조 조절)

  • 김홍승;심규환;이승윤;이정용;강진영
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.13 no.2
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    • pp.95-100
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    • 2000
  • For the well-controlled growing in-situ heavily phosphorus doped polycrystalline Si films directly on Si wafer by reduced pressure chemical vapor deposition, a study is made of the two step growth. When in-situ heavily phosphorus doped Si films were deposited directly on Si (100) wafer, crystal structure in the film is not unique, that is, the single crystal to polycrystalline phase transition occurs at a certain thickness. However, the well-controlled polycrtstalline Si films deposited by two step growth grew directly on Si wafers. Moreover, the two step growth, which employs crystallization of grew directly on Si wafers. Moreover, the two step growth which employs crystallization of amorphous silicon layer grown at low temperature, reveals crucial advantages in manipulating polycrystal structures of in-situ phosphorous doped silicon.

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An Analysis on Structure of Impinging and Free Diesel Spray with Exciplex Fluorescence Method in High Temperature and Pressure Field

  • Yeom, Jeong-Kuk;Park, Jong-Sang;Chung, Sung-Sik
    • Journal of Mechanical Science and Technology
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    • v.19 no.12
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    • pp.2281-2288
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    • 2005
  • Because an injected spray development process consists of impinging and free spray in the diesel engine, it is needed to analyze the impinging spray and free spray, simultaneously, in order to study the diesel spray behavior. To dominate combustion characteristics in diesel engine is interaction between injected fuel and ambient gas, that is, process of mixture formation. Also it is very important to analyze liquid and vapor phases of injected fuel on the investigation of mixing process, respectively and simultaneously. Therefore, in this study, the behavior characteristics of the liquid phase and the vapor phase of diesel spray was studied by using exciplex fluorescence method in high temperature and injection pressure field. Finally, it can be confirmed that the distribution of vapor concentration is more uniform in the case of the high injection than in that of the low injection pressure.

Effect of Heating Rate on Spalling Type of High-Strength Concrete (고강도 콘크리트의 폭렬형태에 미치는 가열속도의 영향)

  • Hwang, Eui-Chul;Kim, Guy-Yong;Son, Min-Jae;Suh, Dong-Kyun;Lee, Yae-Chan;Nam, Jeong-Soo
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2021.05a
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    • pp.237-238
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    • 2021
  • This study evaluated the vapor pressure and thermal stress of high-strength concrete according to spalling type. As a result, it was confirmed that the internal temperature gradient of the concrete varies depending on the heating rate, and the vapor pressure and thermal stress of the concrete are the main factors of spalling. In addition, it was confirmed that spalling type varies depending on the vapor pressure and thermal stress of the concrete.

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Protection of Polaromonas naphthalenivorans CJ2 from Naphthalene Toxicity by Extracellular Polysaccharide Capsules

  • Park, Min-Jeong;Jeon, Ye-Ji;Madsen, Eugene L.;Jeon, Che-Ok
    • Journal of Applied Biological Chemistry
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    • v.50 no.2
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    • pp.41-45
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    • 2007
  • Polaromonas naphthalenivorans CJ2, responsible for naphthalene degradation at a coal tar contaminated site, was isolated on MSB agar media supplied with naphthalene vapor as the sole carbon source at $10^{\circ}C$. The strain is not isolated under the same isolation condition using the same soil sediment at $20^{\circ}C$ although its optimum temperature is about $20^{\circ}C$. In this work we explored the reason why strain CJ2 could not have been isolated on MSB agar with naphthalene vapor at $20^{\circ}C$. Dispersed CJ2 cells in PBS buffer formed colonies on MSB agar with naphthalene vapor at $10^{\circ}C$ with low naphthalene vapor pressure, but not at $20^{\circ}C$ with high naphthalene vapor pressure. However, streaked cells without resuspension grew on MSB agar with naphthalene vapor at $10^{\circ}C,\;20^{\circ}C$, and even $25^{\circ}C$. Investigation of scanning electron microscopy showed that CJ2 cells formed extracellular polysaccharide (EPS) capsules, which were released easily from CJ2 cells by just dispersion. Therefore, it is concluded that strain CJ2 is able to overcome the naphthalene toxicity by forming a capsule-type barrier around the cells although it is susceptible to naphthalene toxicity at high temperature.

Evaluation of Spalling Property and Water Vapor Pressure of Concrete with Heating Rate (가열 속도에 따른 콘크리트의 폭렬 특성 및 내부 수증기압력 평가)

  • Choe, Gyeong-Cheol;Lee, Tae-Gyu;Nam, Jeong-Soo;Park, Byung-Keun;Kim, Gyu-Yong
    • Journal of the Korea Concrete Institute
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    • v.24 no.5
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    • pp.605-612
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    • 2012
  • Spalling of concrete occurs due to vapor pressure ignited explosion, temperature difference across a section, and combination of these factors. Factors affecting spalling can be classified into internal and external factors such as material property and environmental condition, respectively, have to be considered to precisely understand spalling behavior. An external environmental factor such as differences in heating rate cause internal humidity cohesion and different vapor pressure behavior. Therefore, spalling property, vapor pressure and thermal strain property were measured from concrete with compressive strengths of 30 MPa, 50 MPa, 70 MPa, 90 MPa, and 110 MPa, applied with ISO-834 standard heating curve of $1^{\circ}C/min$ heating rate. The experimental results showed that spalling occurred when rapid heating condition was applied. Also, when concrete strength was higher, the more cross section loss from spalling occurred. Also, spalling property is influenced by first pressure cancellation effect of thermal expansion caused by vapor pressure and heating rates.

Improvement of GPS PWV retrieval capability using the reverse sea level corrections of air-pressure (기압의 역해면 경정 보정을 이용한 GPS PWV 복원 능력 개선)

  • Song, Dong-Seob
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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    • v.27 no.5
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    • pp.535-544
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    • 2009
  • Signals from the Global Positioning System(GPS) satellite are used to retrieve the integrated amount of water vapor or the precipitable water vapor(PWV) along the path between a transmitting satellite and ground-based receiver. In order to retrieve the PWV from GPS signal delay in the troposphere, the actual zenith wet delay, which can be derived by extracting the zenith total delay and subtracting the actual zenith hydrostatic delay computed using surface pressure observing, will be needed. Since it has been not co-located between GPS permanent station and automated weather station, the air-pressure on the mean sea level has been used to determine the actual zenith hydrostatic delay. The directly use of this air-pressure has been caused the dilution of precision on GPS PWV retrieval. In this study, Korean reverse sea level correction method of air-pressure was suggested for the improving of GPS PWV retrieval capability and the accuracy of water vapor estimated by GPS was evaluated through a comparison with radiosonde PWV.

The Study on the Fuel Vapor Distribution of Homogeneous Charge in a DISI Engine with a 6-Hole Fuel Injector (6공 연료분사기를 장착한 DISI 엔진 내 균질급기의 연료증기 분포 특성)

  • Kim, S.S.
    • Journal of Power System Engineering
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    • v.15 no.1
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    • pp.5-10
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    • 2011
  • The spatial fuel vapor distribution of the homogeneous charge by a 6-hole injector was examined in a optically accessed single cylinder direct injection spark ignition(DISI) engine. The effects of in-cylinder charge motion, and fuel injection pressure, and coolant temperature were investigated using a planar LIF (Laser Induced Fluorescence) technique. It was confirmed that the in-cylinder tumble flow played a little more effective role in the spatial fuel vapor distribution than the swirl flow during the compression stroke at 10 mm and 2 mm planes under cylinder head gasket and the increased fuel injection pressure activated spatial distributions of the fuel vapor. In additions, richer mixtures were concentrated around the cylinder wall by the increase of the coolant temperature.