scholarly journals Time Variation in the Chemical and Isotopic Composition of Volcanic Gas at Mt. Mihara of Izu-Oshima Island, Japan

2019 ◽  
Vol 14 (7) ◽  
pp. 972-977
Author(s):  
Takeshi Ohba ◽  
Muga Yaguchi ◽  
Kana Nishino ◽  
Nozomi Numanami ◽  
◽  
...  
Keyword(s):  
Water Vapor ◽  
Isotopic Composition ◽  
Time Variation ◽  
Excess Enthalpy ◽  
Vapor Condensation ◽  
Hydrogen Gas ◽  
Volcanic Gas ◽  
Water Vapor Condensation ◽  
Pit Crater ◽  
Fumarolic Gas

Volcanic gas was sampled at three fumaroles and one borehole on Mt. Mihara, Izu-Oshima volcano. The fumarolic gas and the borehole steam possessed an excess enthalpy relative to the air saturated with water vapor. The fumarolic gas located west of the pit crater on Mt. Mihara showed a time variation in chemical and isotopic composition. The cause of the variation seems to be an enhancement of water vapor condensation. No similar variation was observed in the fumarolic gas located east of the pit crater, suggesting the above variation is a phenomena localized around the western fumarole. Hydrogen gas was detected in the sampled gases with low concentration. The change in the H2 concentration synchronized among the three fumaroles, suggesting the H2 gas originated in the hydrothermal system developed beneath Mt. Mihara.

scholarly journals An Experimental Investigation of Water Vapor Condensation from Biofuel Flue Gas in a Model of Condenser, (1) Base Case: Local Heat Transfer without Water Injection

Processes ◽  
2021 ◽  
Vol 9 (5) ◽  
pp. 844
Author(s):  
Robertas Poškas ◽  
Arūnas Sirvydas ◽  
Vladislavas Kulkovas ◽  
Povilas Poškas
Keyword(s):  
Heat Transfer ◽  
Water Vapor ◽  
Flue Gas ◽  
Waste Heat Recovery ◽  
Waste Heat ◽  
Water Injection ◽  
Vapor Condensation ◽  
Base Case ◽  
Water Vapor Condensation ◽  
Condensing Heat Exchanger

Waste heat recovery from flue gas based on water vapor condensation is an important issue as the waste heat recovery significantly increases the efficiency of the thermal power units. General principles for designing of this type of heat exchangers are known rather well; however, investigations of the local characteristics necessary for the optimization of those heat exchangers are very limited. Investigations of water vapor condensation from biofuel flue gas in the model of a vertical condensing heat exchanger were performed without and with water injection into a calorimetric tube. During the base-case investigations, no water was injected into the calorimetric tube. The results showed that the humidity and the temperature of inlet flue gas have a significant effect on the local and average heat transfer. For some regimes, the initial part of the condensing heat exchanger was not effective in terms of heat transfer because there the flue gas was cooled by convection until its temperature reached the dew point temperature. The results also showed that, at higher Reynolds numbers, there was an increase in the length of the convection prevailing region. After that region, a sudden increase was observed in heat transfer due to water vapor condensation.

Water vapor condensation on binary mixed substrates: A molecular dynamics study

2021 ◽  
pp. 122281
Author(s):  
Zi-Jie Wang ◽  
Shao-Yu Wang ◽  
Dan-Qi Wang ◽  
Yan-Ru Yang ◽  
Xiao-Dong Wang ◽  
...  
Keyword(s):  
Molecular Dynamics ◽  
Water Vapor ◽  
Vapor Condensation ◽  
Mixed Substrates ◽  
Water Vapor Condensation

Gasdynamic water-vapor-condensation laser

1975 ◽  
Vol 5 (9) ◽  
pp. 1131-1132
Author(s):  
V K Konyukhov ◽  
A M Prokhorov ◽  
V I Tikhonov ◽  
V N Faizulaev
Keyword(s):  
Water Vapor ◽  
Vapor Condensation ◽  
Water Vapor Condensation

scholarly journals Methods for Determining Mold Development and Condensation on the Surface of Building Barriers

Buildings ◽  
2019 ◽  
Vol 10 (1) ◽  
pp. 4 ◽  
Author(s):  
Aleksander Starakiewicz ◽  
Przemysław Miąsik ◽  
Joanna Krasoń ◽  
Lech Lichołai
Keyword(s):  
Water Vapor ◽  
Vapor Condensation ◽  
Mold Growth ◽  
Vapor Pressures ◽  
Climate Conditions ◽  
Outdoor Climate ◽  
Surface Condensation ◽  
Water Vapor Condensation ◽  
Calculation Results ◽  
Temperature Factors

The article presents four equivalent methods for checking mold growth on the surface of building barriers and checking water vapor condensation on their surface. Each method applies to two parallel phenomena that may occur on a building barrier. The first method is to calculate and compare temperature factors. In the second method, the characteristic humidity in the room is calculated and compared. The third method is to calculate and compare the characteristic temperatures in the room. The fourth method is based on the calculation and comparison of characteristic water vapor pressures. Three boundary conditions are presented for each method and phenomenon: when a given phenomenon can occur, when it begins or ends, and when it does not occur. The presented methods systematize the approach to the problem of mold development and surface condensation. The presented calculation results relate to the selected building barrier functioning in specific indoor and outdoor climate conditions. The calculation results confirm the compliance of the presented methods in identifying the phenomenon of mold growth or condensation on the surface of the barrier. A graphical interpretation of the results for each method with periods of occurrence or absence of a given phenomenon is also presented.

Sign in / Sign up

Export Citation Format

Share Document