Ignition Transients and Pressurization in Closed Chambers

1975 ◽  
Author(s):  
Leonard H. Caveny ◽  
Martin Summerfield ◽  
Carl W. Nelson
Keyword(s):  
Closed Chambers

Hydrogen sulphide inhibits PSII of lichen photobionts

2013 ◽  
Vol 45 (1) ◽  
pp. 101-113 ◽  
Author(s):  
Stefano BERTUZZI ◽  
Mauro TRETIACH
Keyword(s):  
Hydrogen Sulphide ◽  
Vascular Plants ◽  
Solid Phase ◽  
Photosynthetic Apparatus ◽  
Sample Surface ◽  
Gas Chromatography Mass Spectrometry ◽  
Solid Phase Micro Extraction ◽  
Action Mechanisms ◽  
Species Specific ◽  
Closed Chambers

AbstractThe effects of hydrogen sulphide (H2S) on five lichens with different photobionts, ecology, and tolerance to the pollutant were studied by means of samples exposed in closed chambers containing two known H2S solutions. The H2S concentration in the void volume at equilibrium with the liquid phase was measured by gas chromatography-mass spectrometry, combined with the use of solid phase micro extraction (GC/MS SPME). It was determined as 8 and 28 ppm H2S in the absence of lichen material, andc. 2 and 10 ppm H2S respectively with living lichen material inserted for 8 hours in the exposure chambers. Significant differences in the species-specific emission of chlorophyllafluorescence (ChlaF) were observed, with a pronounced depression ofFv/Fmalready detectable after 2 h exposure at 28 ppm H2S in all the species. The decreased intensity was positively correlated to sample surface and, to a lesser extent, to the species-specific pre-exposureFv/Fmvalue. Dark-exposed samples were less affected than light-exposed ones. All four chlorolichens could recover the pre-exposure ChlaF emission after two days in the absence of H2S, both in the light and in the dark, whereas the cyanolichen did not recover when kept in the dark. The results are thoroughly discussed on the basis of the known action mechanisms of H2S on the photosynthetic apparatus of vascular plants and cyanobacteria.

Closed Chambers: The Rise, Fall, and Future of the Modern Supreme Court.

2000 ◽  
Vol 86 (4) ◽  
pp. 1867
Author(s):  
Randall W. Bland ◽  
Edward Lazarus ◽  
David N. Atkinson
Keyword(s):  
Supreme Court ◽  
Closed Chambers

Opening Closed Chambers

1999 ◽  
Vol 108 (5) ◽  
pp. 1087 ◽  
Author(s):  
Erwin Chemerinsky ◽  
Edward P. Lazarus
Keyword(s):  
Closed Chambers

scholarly journals Determination of respiration and photosynthesis fractionation coefficients for atmospheric dioxygen inferred from a vegetation-soil-atmosphere analog of the terrestrial biosphere in closed chambers

2021 ◽  
Author(s):  
Clémence Paul ◽  
Clément Piel ◽  
Joana Sauze ◽  
Nicolas Pasquier ◽  
Frédéric Prié ◽  
...  
Keyword(s):  
Festuca Arundinacea ◽  
Dark Respiration ◽  
Relative Concentration ◽  
Ice Core ◽  
Isotopic Fractionation ◽  
Ice Cores ◽  
Terrestrial Biosphere ◽  
Soil Atmosphere ◽  
Photosynthetic Fractionation ◽  
Closed Chambers

Abstract. The isotopic composition of dioxygen in the atmosphere is a global tracer which depends on the biosphere flux of dioxygen toward and from the atmosphere (photosynthesis and respiration) as well as exchanges with the stratosphere. When measured in fossil air trapped in ice cores, the relative concentration of 16O, 17O and 18O of O2 can be used for several applications such as ice core dating and past global productivity reconstruction. However, there are still uncertainties about the accuracy of these tracers as they depend on the integrated isotopic fractionation of different biological processes of dioxygen production and uptake, for which we currently have very few independent estimates. Here we determined the respiration and photosynthesis fractionation coefficients for atmospheric dioxygen from experiments carried out in a replicated vegetation-soil-atmosphere analog of the terrestrial biosphere in closed chambers with growing Festuca arundinacea. The values for 18O discrimination during soil respiration and dark respiration in leave are equal to −12.3 ± 1.7 ‰ and −19.1 ± 2.4 ‰, respectively. We also found a value for terrestrial photosynthetic fractionation equal to +3.7 ± 1.3 ‰. This last estimate suggests that the contribution of terrestrial productivity in the Dole effect may have been underestimated in previous studies.

scholarly journals Increasing sensitivity of methane emission measurements in rice through deployment of ‘closed chambers’ at nighttime

PLoS ONE ◽  
2018 ◽  
Vol 13 (2) ◽  
pp. e0191352 ◽  
Author(s):  
Reiner Wassmann ◽  
Ma. Carmelita Alberto ◽  
Agnes Tirol-Padre ◽  
Nghia Trong Hoang ◽  
Ryan Romasanta ◽  
...  
Keyword(s):  
Methane Emission ◽  
Closed Chambers
Sign in / Sign up

Export Citation Format

Share Document