Isotopic fractionation between gaseous and condensed carbon dioxide

1969 ◽  
Vol 221 (3) ◽  
pp. 257-273 ◽  
Author(s):  
P. M. Grootes ◽  
W. G. Mook ◽  
J. C. Vogel
Keyword(s):  
Carbon Dioxide ◽  
Isotopic Fractionation ◽  
Condensed Carbon

An applied mineralogical investigation of concrete degradation in a major concrete road bridge

1990 ◽  
Vol 54 (377) ◽  
pp. 637-644 ◽  
Author(s):  
G. Macleod ◽  
A. J. Hall ◽  
A. E. Fallick
Keyword(s):  
Carbon Dioxide ◽  
Cement Paste ◽  
Atmospheric Carbon Dioxide ◽  
Meteoric Water ◽  
Isotope Analysis ◽  
Isotopic Fractionation ◽  
Physical Growth ◽  
Carbon Isotopic ◽  
Mineralogical Investigation ◽  
Atmospheric Carbon

AbstractA core of concrete taken from a major road bridge in the Strathclyde Region, Scotland, has been subjected to an applied mineralogical investigation, which involved stable isotope analysis, petrography, X-ray diffraction and scanning electron microscopy.The structure is actively undergoing severe degradation due to mineral growth which is related to chemical reactions between the concrete and pore fluid. The physical growth of minerals causes disfigurement and structural weakening.Pyrite and pyrrhotine hosted by dolerite aggregate appear to have been oxidized, providing sulphate for the deposition of ettringite and minor gypsum, in spheroidal cavities within the cement paste. The rainwater which passes through the structure mobilising sulphate from original gypsum in the paste and oxidizing the iron sulphides is also involved in the further leaching of elements from the cement paste and in the deposition of calcite. The isotopic values of calcites forming a crust on the concrete and a stalactite under the bridge are similar with δ13C= −19‰ PDB and δ18‰= +16‰ SMOW. We suggest that atmospheric carbon dioxide was the carbon source. The carbon isotopic fractionation of −12‰ from atmospheric carbon dioxide of δ13C= −7‰, (O'Neil and Barnes, 1971) can best be explained as due to a kinetic fractionation related to the hyper-basicity of the pore water. The equilibrium formation temperature of about 45°C calculated from the oxygen isotope values and assuming a δ18O value of meteoric water of −8‰ SMOW, is considered unreasonable. The exceptionally low δ18O values are attributed mainly to reaction kinetics and the calcite inheriting its oxygen, two-thirds from atmospheric carbon dioxide and one third from the meteoric formation water (O'Neil and Barnes, 1971). A δ18O value of atmospheric carbon dioxide of +41‰ SMOW and a δ18O value of meteoric water of −8‰ SMOW, lead to a calculated δ18O value for the calcites of +10‰ SMOW. The calcites analysed have a value of +16‰ and this may be due to partial re-equilibration towards a calculated value of +21‰ for calcite in equilibrium with the meteoric water at 20°C.

scholarly journals Gliwice Radiocarbon Dates VII

Radiocarbon ◽  
1982 ◽  
Vol 24 (2) ◽  
pp. 171-181 ◽  
Author(s):  
Anna Pazdur ◽  
Romuald Awsiuk ◽  
Andrzej Bluszcz ◽  
Mieczysław F Pazdur ◽  
Adam Walanus ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
Oxalic Acid ◽  
Integrated Circuit ◽  
Proportional Counter ◽  
Isotopic Fractionation ◽  
Radiocarbon Dates ◽  
Unknown Sample ◽  
Proportional Counters ◽  
Typical Measurement ◽  
Contemporary Standard

The following list contains the measurements of archaeologic samples made during 1978 and 1979 using carbon-dioxide-filled proportional counters. Most of the samples were dated with counter No. 3 (L3) filled to 1 or 2 atm pressure (Mościcki and Zastawny, 1977). Our counter No. 1 (L1) previously described (Mościcki and Zastawny, 1976) has been remounted and is now operating at 2 atm pressure of carbon dioxide. Samples measured with this counter have date numbers starting with Gd-1000. Parameters of proportional counters are listed in Table 1. Our transistorized electronics is being gradually replaced by more compact integrated-circuit electronics in CAMAC system (Bluszcz and Walanus, 1980). Counts from proportional counter and guard counters are recorded in 5 channels and punched every 100 minutes. Typical measurement of any sample, including background and oxalic acid samples, consists of a series of 20 to 25 partial measurements. Partial results obtained in such series are analyzed on ODRA 1325 computer at the Computing Centre of the Silesian Technical University according to code C14C written in ALGOL (Pazdur and Walanus, 1979). Age calculations are based on contemporary value equal to 0.95 of the activity of NBS oxalic acid standard and on the Libby value for the half-life of radiocarbon. Ages are reported as conventional radiocarbon dates in years before ad 1950. Corrections for isotopic fractionation in nature are made only for some samples with indicated values of δ13C Errors quoted (±1σ) include estimated overall standard deviations of count rates of the unknown sample, contemporary standard, and background (Pazdur and Walanus, 1979).

Adsorption of hydrogen by condensed carbon dioxide at 20 K

Cryogenics ◽  
1974 ◽  
Vol 14 (10) ◽  
pp. 557-558 ◽  
Author(s):  
L. Bewilogua ◽  
M. Jäckel
Keyword(s):  
Carbon Dioxide ◽  
Condensed Carbon ◽  
Adsorption Of Hydrogen

Carbon and Oxygen Isotope Fractionation of Pressurized CO2 as a Function of Temperature

2020 ◽  
Author(s):  
Tracey Jacksier ◽  
Rick Socki
Keyword(s):  
Phase Transition ◽  
Carbon Dioxide ◽  
Elevated Temperatures ◽  
Isotopic Fractionation ◽  
Oxygen Isotope Fractionation ◽  
Cold Temperatures ◽  
Carbon And Oxygen Isotope ◽  
To Come ◽  
Gas Expansion ◽  
Liquid Vapor

<p>During liquid-vapor phase transition, CO<sub>2</sub> can undergo isotopic fractionation in both C and O.  This phase transition can occur during routine cylinder handling, such as gas expansion or while subjecting the cylinder to cold temperatures without allowing the cylinders to come to thermal equilibrium prior to use. </p><p>This work examines the isotope changes for both C and O in a series of controlled experiments on dual phase (liquid-vapor) and single-phase (vapor only) carbon dioxide contained in pressurized gas cylinders at sub-freezing, ambient and elevated temperatures.  The isotopic values were measured during the temperature equilibration from either cold or elevated temperatures to room temperature.  Isotopic values were observed to vary when the gas was at sub-freezing temperatures but not from elevated temperatures.  Stable isotope practitioners, who rely on pressurized carbon dioxide as a working IRMS laboratory reference gas, will find this work useful.</p>

scholarly journals Validation of carbon isotope fractionation in algal lipids as a <i>P</i>CO<sub>2</sub> proxy using a natural CO<sub>2</sub> seep (Shikine Island, Japan)

2019 ◽  
Author(s):  
Caitlyn R. Witkowski ◽  
Sylvain Agostini ◽  
Ben P. Harvey ◽  
Marcel T. J. van der Meer ◽  
Jaap S. Sinninghe Damste ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
Atmospheric Carbon Dioxide ◽  
Isotopic Fractionation ◽  
Culture Studies ◽  
Carbon Dioxide Concentrations ◽  
Integral Role ◽  
Mesocosm Experiments ◽  
Long Term Trends ◽  
Species Specific

Abstract. Carbon dioxide concentrations in the atmosphere play an integral role in many earth system dynamics, including its influence on global temperature. Long-term trends can provide insights into these dynamics though reconstructing long-term trends of atmospheric carbon dioxide (expressed in partial pressure; PCO2) remains a challenge in paleoclimatology. One promising approach for reconstructing past PCO2 utilizes isotopic fractionation associated with CO2-fixation during photosynthesis into organic matter (Ɛp). Previous studies have focused primarily on testing estimates of Ɛp derived from species-specific alkenone compounds in laboratory cultures and mesocosm experiments. Here, we analyze Ɛp derived from general algal compounds from sites at a CO2 seep near Shikine Island (Japan), a natural environment with CO2 concentrations ranging from ambient (ca. 310 µatm) to elevated (ca. 770 µatm). We observed strong, consistent δ13C shifts in several algal biomarkers from a variety of sample matrices over the steep CO2 gradient. Of the three general algal biomarkers explored here, namely loliolide, phytol, and cholesterol, Ɛp positively correlates with PCO2 in agreement with Ɛp theory and previous culture studies. PCO2 reconstructed from the Ɛp of general algal biomarkers show the same trends throughout, as well as the correct control values, but with lower absolute reconstructed values than the measured values at the elevated PCO2 sites. Our results show that naturally-occurring CO2 seeps may provide useful testing grounds for PCO2 proxies and that general algal biomarkers show promise for reconstructing past PCO2.

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