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 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 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 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 Tartu Radiocarbon Dates XII

Radiocarbon ◽  
1991 ◽  
Vol 33 (3) ◽  
pp. 345-354
Author(s):  
Evald Ilves
Keyword(s):  
Standard Deviation ◽  
Oxalic Acid ◽  
Half Life ◽  
Liquid Scintillation ◽  
Standard Sample ◽  
Single Channel ◽  
Geological Samples ◽  
Radiocarbon Dates ◽  
Modern Standard

IntroductionThis list includes dates of geological samples measured using a single-channel liquid scintillation 14C counter at the Geochemical and Statistical Laboratory, Tartu, Estonia. 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 years. A.D. 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 Physical Research Laboratory Radiocarbon Date List VI

Radiocarbon ◽  
1991 ◽  
Vol 33 (3) ◽  
pp. 329-344 ◽  
Author(s):  
D. P. Agrawal ◽  
Sheela Kusumgar ◽  
M. G. Yadava
Keyword(s):  
Standard Deviation ◽  
Oxalic Acid ◽  
Proportional Counter ◽  
Research Laboratory ◽  
Radiocarbon Date ◽  
Geological Samples ◽  
Physical Research Laboratory ◽  
Detailed Procedure ◽  
Counting Statistics ◽  
Modern Standard

We present here dates for archaeological and geological samples. The dates are based on τ1/2 = 5568 years, using 1950 as the base year. The modern standard was 95% of activity of NBS oxalic acid.Samples were pretreated, prepared by methane synthesis and counted in a proportional counter. The detailed procedure has been described earlier (Agrawal, Gupta & Kusumgar 1971). We reported minor changes in previous date lists. Quoted errors are based on counting statistics alone. For samples younger than 10,000 years, the error is 1 standard deviation, and for older samples, 2 standard deviations. The dates are not corrected for 13C fractionation. Samples have been arranged alphabetically according to the name of the site.

scholarly journals Tallinn Radiocarbon Dates VI

Radiocarbon ◽  
1980 ◽  
Vol 22 (1) ◽  
pp. 91-98 ◽  
Author(s):  
J M Punning ◽  
R Rajamäe ◽  
K Joers ◽  
H Putnik
Keyword(s):  
Oxalic Acid ◽  
Half Life ◽  
Radiocarbon Dates ◽  
Academy Of Sciences ◽  
Modern Standard

The following list includes samples dated at the Institute of Geology, Academy of Sciences of the Estonian SSR in 1978. The measurement of natural 14C activity is performed by 1-channel and 2-channel scintillation devices (Punning & Rajamäe, 1977). Ages are calculated using the half-life of 5568 ± 30 years and 0.95 NBS oxalic acid modern standard with ad 1950 as reference year.

scholarly journals U. S. Geological Survey Radiocarbon Dates VI

Radiocarbon ◽  
1961 ◽  
Vol 3 ◽  
pp. 86-98 ◽  
Author(s):  
Meyer Rubin ◽  
Sarah M. Berthold
Keyword(s):  
Oxalic Acid ◽  
19Th Century ◽  
Half Life ◽  
Geological Survey ◽  
Radiocarbon Dates ◽  
Appreciable Difference ◽  
The 19Th Century ◽  
Modern Standard

Dates in this list have been determined at U. S. Geological Survey radiocarbon laboratory, Washington, since our 1960 date list (USGS V). Procedures for the preparation of acetylene gas used in the counting, and the method of counting, (two days in two separate counters) remain unchanged. However, the modern standard used is no longer wood grown in the 19th century, but 95% of the activity of NBS oxalic-acid radiocarbon standard, as recommended at the 1959 Groningen Radiocarbon Conference. Measurement of the oxalic-acid standard at our laboratory indicates 6.2 ± 1% more C14 activity than our modern wood standard; so use of the new standard should make no appreciable difference when comparing samples computed by the old method. W. F. Libby's (1955) half-life average for C14, 5568 ± 30 years, was used for the decay equation.

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 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.

Sign in / Sign up

Export Citation Format

Share Document