scholarly journals Lódź Radiocarbon Dates II

Radiocarbon ◽  
1986 ◽  
Vol 28 (3) ◽  
pp. 1102-1109 ◽  
Author(s):  
Andrzej Kanwiszer ◽  
Paweł Trzeciak
Keyword(s):  
Standard Deviation ◽  
Proportional Counter ◽  
Half Life ◽  
Radiocarbon Dates ◽  
Geologic Samples ◽  
Modern Standard

The following list consists of dates of archaeologic and geologic samples measured from January 1981 to December 1982. Measurements were continued with the same proportional counter system, pretreatment procedure, methane preparation, measurement, and calculation, as described previously (Kanwiszer & Trzeciak, 1984). Ages were computed on the 14C half-life of 5568 ± 30 years. Precision is reported as one standard deviation based only on statistical counting uncertainties in the measurement of the background, NBS modern standard, and sample activities. The dates are not corrected for 13C fractionation. Descriptions and comments are based on information supplied by submitters of samples.

scholarly journals National Taiwan University Radiocarbon Measurements II

Radiocarbon ◽  
1973 ◽  
Vol 15 (2) ◽  
pp. 345-349 ◽  
Author(s):  
Yuin-Chi Hsu ◽  
Muh-Chen Chou ◽  
Yi-Chuan Hsu ◽  
Song-Yun Lin ◽  
Shih-Chong Lu
Keyword(s):  
Standard Deviation ◽  
Oxalic Acid ◽  
Proportional Counter ◽  
Half Life ◽  
Statistical Nature ◽  
Radiocarbon Dates ◽  
Disintegration Process ◽  
Modern Standard

The C14 dates given below have been obtained by counting CO2 at 2 atm pressure in a 1 L proportional counter. Details of procedure are given in our previous list (R., 1970, v. 12, p. 187–192). Radiocarbon dates in this list are based on 95% of activity of NBS oxalic acid as the modern standard and were calculated using 5570 yr as the half-life of C14. Errors quoted with the dates are standard deviation originating from the statistical nature of radioactive disintegration process. Results obtained during 1970 and 1971 are described here.

scholarly journals University of Miami Radiocarbon Dates IX

Radiocarbon ◽  
1977 ◽  
Vol 19 (2) ◽  
pp. 326-331 ◽  
Author(s):  
D Piepgras ◽  
J J Stipp
Keyword(s):  
Standard Deviation ◽  
Half Life ◽  
Radiocarbon Dates ◽  
Partial List ◽  
Geologic Samples ◽  
University Of Miami ◽  
Modern Standard

The following radiocarbon measurements are a partial list of geologic samples dated since September 1975. The technique used is described in R, v 18, p 210-220. Dates are calculated using a 14C half-life of 5568 yr and errors are reported as one standard deviation. This includes only the counting errors on the sample, background and modern standard.

scholarly journals University of Miami Radiocarbon Dates XI

Radiocarbon ◽  
1978 ◽  
Vol 20 (1) ◽  
pp. 134-138 ◽  
Author(s):  
D Piepgras ◽  
M M Calvert ◽  
J J Stipp
Keyword(s):  
Standard Deviation ◽  
Half Life ◽  
Radiocarbon Dates ◽  
Unknown Sample ◽  
Partial List ◽  
Geologic Samples ◽  
University Of Miami ◽  
Modern Standard

The following dates are a partial list of geologic samples dated since December 1976. The method used is described by (Stipp et al, 1976). Ages were calculated using a half-life of 5568 years. Errors reported are one standard deviation and include only the counting errors on the unknown sample, background and modern standard. There have been no corrections made on these dates. Sample descriptions and comments were written, based on information supplied by the submitters.

scholarly journals Tartu Radiocarbon Dates XI

Radiocarbon ◽  
1990 ◽  
Vol 32 (1) ◽  
pp. 99-105 ◽  
Author(s):  
Evald Ilves
Keyword(s):  
Standard Deviation ◽  
Oxalic Acid ◽  
Half Life ◽  
Liquid Scintillation ◽  
Standard Sample ◽  
Single Channel ◽  
Radiocarbon Dates ◽  
Geologic Samples ◽  
Modern Standard

This list includes dates of geologic samples measured using a single-channel liquid scintillation 14C counter at the Geochemical and Statistical Laboratory, Tartu, Estonian SSR. Our modern standard is made of benzene enriched in 14C and its activity is checked with NBS oxalic acid standard sample. Dates are given in conventional radiocarbon years, based on the Libby half-life of 5570 ± 30 yr. AD 1950 is the reference year. Errors refer only to 1σ standard deviation calculated from count rates involved.

scholarly journals University of Miami Radiocarbon Dates XVI

Radiocarbon ◽  
1979 ◽  
Vol 21 (3) ◽  
pp. 477-483
Author(s):  
D S Introne ◽  
R Johnson ◽  
J J Stipp
Keyword(s):  
Standard Deviation ◽  
Half Life ◽  
Isotopic Fractionation ◽  
Radiocarbon Dates ◽  
Marine Carbonates ◽  
Age Correction ◽  
University Of Miami ◽  
Reservoir Age ◽  
Modern Standard

Radiocarbon measurements have been continued on a variety of projects and materials. Chemical and counting procedures remain the same as indicated in R, v 20, p 274-282. Dates are calculated using the Libby 14C half-life of 5568 years; errors are reported as one-standard deviation (1σ) based only on statistical counting uncertainties in background, modern standard, and sample activities. All samples for which 13C/12C ratios are available are corrected for isotopic fractionation by normalizing to —25‰. A 400-year reservoir age correction has been applied to marine carbonates.

scholarly journals Tartu Radiocarbon Dates XIII

Radiocarbon ◽  
1994 ◽  
Vol 36 (1) ◽  
pp. 153-158
Author(s):  
Arvi Liiva ◽  
Ilze Loze
Keyword(s):  
Standard Deviation ◽  
Oxalic Acid ◽  
Liquid Scintillation Counting ◽  
Half Life ◽  
Liquid Scintillation ◽  
Standard Sample ◽  
Scintillation Counting ◽  
Radiocarbon Dates ◽  
Academy Of Sciences ◽  
Modern Standard

This date list reports dates of archaeological samples of Mesolithic and Neolithic sites of Estonia, Latvia and Lithuania. We use liquid scintillation counting at the Geochemical and Statistical Laboratory of the Institute of Zoology and Botany, Estonian Academy of Sciences. Our modern standard is benzene enriched in 14C and its activity is checked with an NBS oxalic acid standard sample. Dates are given in conventional 14C years, based on the Libby half-life of 5570 ± 30 yr. AD 1950 is the reference year. Errors are based on one standard deviation calculated from count rates.

scholarly journals University of Miami Radiocarbon Dates XXIII

Radiocarbon ◽  
1983 ◽  
Vol 25 (3) ◽  
pp. 930-935 ◽  
Author(s):  
D G Hood ◽  
R A Johnson ◽  
J J Stipp
Keyword(s):  
Standard Deviation ◽  
Half Life ◽  
Isotopic Fractionation ◽  
Radiocarbon Dates ◽  
Partial List ◽  
University Of Miami ◽  
Modern Standard

The following radiocarbon dates are a partial list of samples measured for a variety of projects and materials since May 1982. Chemical and counting procedures remain the same as indicated in R, v 20, p 274–282.Calculations are based on the 5568-year Libby 14C half-life. Precision is reported as one-standard deviation based only on statistical counting uncertainties in the measurement of the background, NBS modern standard, and sample activities. δ13C values are measured relative to PDB and reported ages are corrected for isotopic fractionation by normalizing to −25‰.

scholarly journals Gif Natural Radiocarbon Measurements IX

Radiocarbon ◽  
1982 ◽  
Vol 24 (3) ◽  
pp. 291-343 ◽  
Author(s):  
Georgette Delibrias ◽  
Marie-Thérèse Guillier ◽  
Jacques Labeyrie
Keyword(s):  
Standard Deviation ◽  
South America ◽  
Oxalic Acid ◽  
West Africa ◽  
Sea Level ◽  
Half Life ◽  
Sea Level Variations ◽  
Geologic Samples ◽  
Modern Standard

The following list includes 14C measurements of geologic samples, the majority of which pertain to sea-level variations, and of archaeologic samples mainly from France, West Africa, and South America. Most of the dates were measured between 1972 and 1973 when installations were not modified. The technique used is described in Radiocarbon, 1972, v 14, p 280–320. Dates were calculated using the 14C half-life of 5568 years; modern standard is 0.95 of the NBS oxalic acid. Reported errors are one standard deviation for 2000 minutes measurements.

scholarly journals Birmingham University Radiocarbon Dates II

Radiocarbon ◽  
1968 ◽  
Vol 10 (2) ◽  
pp. 200-206 ◽  
Author(s):  
F. W. Shotton ◽  
D. J. Blundell ◽  
R. E. G. Williams
Keyword(s):  
Statistical Analysis ◽  
Standard Deviation ◽  
Proportional Counter ◽  
Half Life ◽  
Background Count ◽  
Radiocarbon Dates ◽  
Double Ring

Measurements have continued with the 6 L counter which has proved reliable at pressures as high as 2.6 atm and as low as 0.3 atm. It has now been enclosed in a double ring of 27 geiger tubes which has reduced the background count to 10 cpm at 2 atm. So far, we have had no success with the 1.5 L Oeschger-type proportional counter. Failure to obtain steady readings is probably due to continued outgassing from the teflon insulation. All insulating parts have now been remanufactured from the same source of teflon as was used in the 6 L counter, and the Oeschger counter is being reassembled.Results are still given without correction for δC13. Errors quoted refer only to the standard deviation calculated from a statistical analysis of count rates and the Libby half-life of 5570 ± 30 yr.

scholarly journals University of Miami Radiocarbon Dates X

Radiocarbon ◽  
1977 ◽  
Vol 19 (3) ◽  
pp. 453-459
Author(s):  
D Piepgras ◽  
M A Allison ◽  
T Dlugos ◽  
J J Stipp
Keyword(s):  
Standard Deviation ◽  
Radiocarbon Dates ◽  
Unknown Sample ◽  
Partial List ◽  
Geologic Samples ◽  
University Of Miami ◽  
Modern Standard

The following dates are a partial list of archaeologic and geologic samples measured since spring of 1976. The method used is described by (Stipp et al, 1976). Errors reported are one standard deviation and include only the counting errors on the unknown sample, background, and modern standard. No corrections have been made on these dates. Sample descriptions and comments are based on information supplied by the submitters.

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