Validation of Flux Chamber Technique for Estimating Gas Emission in Situ from Naturally-Ventilated Facilities

2007 ◽  
Author(s):  
Eileen Fabian Wheeler ◽  
Patrick A Topper ◽  
Tom L Richard
Keyword(s):  
Flux Chamber ◽  
Gas Emission ◽  
Chamber Technique

scholarly journals Analyses of In-situ Measurements of Gas Emission and Gas Pressure in Pre-drainage Boreholes in Coal Seams.

1993 ◽  
Vol 109 (5) ◽  
pp. 331-335
Author(s):  
Ken GOTOH ◽  
Tomohiro MURAKAMI ◽  
Hidefumi OHMUTA
Keyword(s):  
In Situ Measurements ◽  
Gas Pressure ◽  
Coal Seams ◽  
Gas Emission

Measurement of carbon dioxide fluxes in a free-air carbon dioxide enrichment experiment using the closed flux chamber technique

2011 ◽  
Vol 45 (1) ◽  
pp. 208-214 ◽  
Author(s):  
Merete Bang Selsted ◽  
Per Ambus ◽  
Anders Michelsen ◽  
Leon van der Linden ◽  
Klaus Steenberg Larsen ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
Carbon Dioxide Enrichment ◽  
Flux Chamber ◽  
Carbon Dioxide Fluxes ◽  
Free Air ◽  
Chamber Technique

Evaluation of the pressure chamber technique for measurement of leaf water potential in cassava (Manihot species)

1978 ◽  
Vol 56 (14) ◽  
pp. 1638-1641 ◽  
Author(s):  
I. F. Ike ◽  
G. W. Thurtell ◽  
K. R. Stevenson
Keyword(s):  
Water Potential ◽  
Leaf Water Potential ◽  
Pressure Chamber ◽  
Leaf Water ◽  
Dew Point ◽  
Manihot Esculenta Crantz ◽  
Osmotic Potentials ◽  
Chamber Technique ◽  
Cassava Varieties

The pressure chamber technique was evaluated as a method for estimating leaf water potential in cassava (Manihot esculenta Crantz). Xylem pressure potentials (ψP) measured with the pressure chamber were compared with leaf water potential (ψL) obtained for the same leaf with the in situ dew-point hygrometer.In both cassava varieties studied, ψL and ψP were linearly related (r2 = 0.87 and 0.98 for CMC9 and CMC40 respectively). The length of petiole exposed outside the chamber affects the relation between ψL and ψP and should be kept at between 1 and 3 cm for better agreement. In CMC40, ψP was consistently lower (drier) than ψL by about 1.0 bar (1 bar = 100 kPa) in the entire range of water potential studied, but was not the case in CMC9. The reason for this difference is unclear but may be due to a filling of tissues other than xylem tissues (Boyer 1967) during the measurement of ψP in CMC40. Average xylem osmotic potentials (ψS) were low (−1.0 ± 0.2 bars and −1.0 ± 0.4 bars for CMC9 and CMC40 respectively). It is, therefore, unnecessary to correct for ψS when using the pressure chamber to estimate leaf water potentials in cassava.

Benthic oxygen flux in the highly productive subarctic Lake Myvatn, Iceland: In situ benthic flux chamber study

2004 ◽  
Vol 38 (2) ◽  
pp. 177-189 ◽  
Author(s):  
Ingunn María Thorbergsdóttir ◽  
Sigurdur Reynir Gíslason ◽  
Haraldur R. Ingvason ◽  
Árni Einarsson
Keyword(s):  
Benthic Flux ◽  
Oxygen Flux ◽  
Flux Chamber ◽  
Chamber Study ◽  
Subarctic Lake ◽  
Lake Mývatn

scholarly journals CO2 and Radon Emissions as Precursors of Seismic Activity

2021 ◽  
Author(s):  
Simone D’Incecco ◽  
Ermioni Petraki ◽  
Georgios Priniotakis ◽  
Michail Papoutsidakis ◽  
Panayiotis Yannakopoulos ◽  
...  
Keyword(s):  
Seismic Activity ◽  
Sampling Methods ◽  
Anomalous Behavior ◽  
Gas Emission ◽  
Short Term ◽  
Radon Gas ◽  
Seismic Precursor ◽  
The Relationship ◽  
Passive Techniques ◽  
Chamber Technique

AbstractThis paper reports a review on the relationship between seismic activity and the emissions of CO2 and radon. Direct, indirect and sampling methods are mainly employed to measure CO2 flux and concentration in seismic areas. The accumulation chamber technique is the mostly used in the literature. Radon gas emission in seismic areas can be considered as a short-term pre-seismic precursor. The study and the measurement of radon gas activity prior to earthquakes can be performed through active techniques, with the use of high-precision active monitors and through passive techniques with the use of passive detectors. Several investigators report models to explain the anomalous behavior of in-earth fluid gasses prior to earthquakes. Models are described and discussed.

scholarly journals Prediction of Coal Mine Gas Emission Quantity Based on Grey-Gas Geologic Method

2018 ◽  
Vol 2018 ◽  
pp. 1-7
Author(s):  
Wang Wei ◽  
Peng Lei ◽  
Wang Xiaochao
Keyword(s):  
Forecast Accuracy ◽  
High Accuracy ◽  
Forecasting Model ◽  
Test Results ◽  
Gas Emission ◽  
Factors Affecting ◽  
In Situ Data ◽  
Coal Mine Gas ◽  
Main Factor

To improve the accuracy and reliability of gas emission prediction, the various factors affecting the amount of gas emission were researched and the main factor determining the amount of gas emission was determined by the gas geology theory. In this paper, we adopted grey-gas geologic method and grey relevancy analysis separately to estimate forecast accuracy and to establish the grey systematic forecasting model; meanwhile, two residual tests were carried out. Combined with the concurrent in situ data, the result of the grey systematic prediction model is verified. The later residual test results indicated that the model is of a high accuracy and the prediction result is reliable, manifesting the method of grey-gas geologic method is a better way to forecast the gas emission.

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