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 Physical Research Laboratory Radiocarbon Date List V

Radiocarbon ◽  
1985 ◽  
Vol 27 (1) ◽  
pp. 95-110 ◽  
Author(s):  
D P Agrawal ◽  
R V Krishnamurthy ◽  
Sheela Kusumgar
Keyword(s):  
Standard Deviation ◽  
Oxalic Acid ◽  
Research Laboratory ◽  
Radiocarbon Date ◽  
Physical Research Laboratory ◽  
Physical Research ◽  
Geologic Samples ◽  
Standard Deviations ◽  
Counting Statistics ◽  
Modern Standard

We report here dates on archaeologic and geologic samples. The samples were counted as methane in gas proportional counters. The techniques used have been described earlier (R, 1971, v 13, p 442–449). Dates are expressed in years BP, taking AD 1950 as the reference year. Modern standard was NBS oxalic acid. Quoted errors are based on counting statistics alone and are equivalent to ±1 standard deviation for samples younger than 10,000 years and ± 2 standard deviations for older samples. Descriptions and references regarding the samples have been supplied by the submitters of the 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 Teledyne Isotopes Radiocarbon Measurements XII

Radiocarbon ◽  
1981 ◽  
Vol 23 (3) ◽  
pp. 329-344 ◽  
Author(s):  
James Buckley ◽  
Cynthia Valdes-Pages
Keyword(s):  
Standard Deviation ◽  
Oxalic Acid ◽  
Half Life ◽  
Counting Statistics ◽  
Modern Standard

This date list reports samples completed before 1979. Methods, equipment, and techniques were reported previously (R, 1968, v 10, p 246; R, 1970, v 12, p 87). Age calculations are based on the conventional 14C half-life of 5568 years. The working laboratory standard is 95% of the NBS oxalic acid standard (SRM 4990). Results are reported in years before 1950 and the standard deviation is based on counting statistics of sample, background, and modern standard. Corrections for δ13C are not included.

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 Rudjer Bošković Institute Radiocarbon Measurements VI

Radiocarbon ◽  
1981 ◽  
Vol 23 (3) ◽  
pp. 410-421 ◽  
Author(s):  
Dušan Srdoč ◽  
Adela Sliepčevic ◽  
Bogomil Obelic ◽  
Nada Horvatinčic
Keyword(s):  
Oxalic Acid ◽  
Soil Sample ◽  
Half Life ◽  
Sample Pretreatment ◽  
Radiocarbon Date ◽  
Sample Treatment ◽  
New Techniques ◽  
Counting Technique ◽  
Acid Sample ◽  
Modern Standard

The following radiocarbon date list contains dates of samples measured since our previous list (R, 1979, v 21, p 131-137). As before, age calculations are based on the Libby half-life 5570 ± 30 yr and reported in years before 1950. The modern standard is 0.95 of the activity of NBS oxalic acid. Sample pretreatment, combustion, and counting technique are essentially the same as described in R, 1971, v 13, p 135-140, supplemented by new techniques for groundwater processing (R, 1979, v 21, p 131-137) and for soil sample treatment (R, 1977, v 19, p 465-475).

scholarly journals University of Texas At Austin Radiocarbon Dates XIII

Radiocarbon ◽  
1979 ◽  
Vol 21 (2) ◽  
pp. 257-273 ◽  
Author(s):  
S Valastro ◽  
E Mott Davis ◽  
Alejandra G Varela
Keyword(s):  
Oxalic Acid ◽  
National Science Foundation ◽  
Liquid Scintillation ◽  
Scintillation Counting ◽  
Radiocarbon Dates ◽  
University Of Texas ◽  
National Science ◽  
Sample Count ◽  
Counting Statistics ◽  
Modern Standard

This list reports certain 14C measurements completed by November 1978; other projects completed by this time will be reported later. Age calculations are based on 14C half-life of 5568yr and modern standard of 95% NBS oxalic acid, supplemented by tree rings of pre-industrial wood from a log cut in the 1850's (Tx-540; R, 1970, v 12, p 249). Deviations reported are based on counting statistics of sample, background and modern, and are ± 1σ, except that when sample count approaches either modern or background, 2σ limits are reported. Unless noted, 12C/13C measurements were not made and results are not corrected for 13C fractionation (assumed ratio = −25‰ WRT PDB). Our laboratory uses liquid scintillation counting of benzene, with Li2C2 and vanadium-activated catalyst in preparation; chemical yields range between 95% and 99%. Three counters are employed; a Packard Tri-Carb Model 3002 and 2 Beckman LS320 spectrometers obtained through a grant from the National Science Foundation.

scholarly journals Tata Institute Radiocarbon Date List II

Radiocarbon ◽  
1964 ◽  
Vol 6 ◽  
pp. 226-232 ◽  
Author(s):  
D. P. Agrawal ◽  
S. Kusumgar ◽  
D. Lal ◽  
R. P. Sarna
Keyword(s):  
Oxalic Acid ◽  
Proportional Counter ◽  
Half Life ◽  
Radiocarbon Date ◽  
Naoh Pretreatment ◽  
Tata Institute ◽  
Gas Proportional Counter ◽  
Inorganic Fraction

The C14 dates presented here have been obtained by counting acetylene, synthesised from the sample, in an Oeschger-Houtermans’ gas proportional counter. The chemical and counting procedures have been described in some detail (Kusumgar et al., 1963a).Dates are based on the C14 half-life value of 5568 yr. For conversion of b.p. dates to a.d./b.c. scale, a.d. 1950 has been taken as the reference yr. Ninety-five % activity of NBS oxalic acid has been adopted as the value for the pre-1900 age-corrected wood.All samples were treated with dilute HCl. Whenever NaOH pretreatment was possible, it has been mentioned in the date list. In the case of bones, only the inorganic fraction has been dated.

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 Texas at Austin Radiocarbon Dates XII

Radiocarbon ◽  
1978 ◽  
Vol 20 (2) ◽  
pp. 245-273 ◽  
Author(s):  
S Valastro ◽  
E Mott Davis ◽  
Alejandra G Varela
Keyword(s):  
Oxalic Acid ◽  
National Science Foundation ◽  
Liquid Scintillation ◽  
Scintillation Counting ◽  
Radiocarbon Dates ◽  
University Of Texas ◽  
National Science ◽  
Sample Count ◽  
Counting Statistics ◽  
Modern Standard

This list reports certain 14C measurements completed by November 1977; other projects completed by this time will be reported later. Age calculations are based on 14C half-life of 5568yr and modern standard of 95% NBS oxalic acid, supplemented by tree rings of pre-industrial wood from a log cut in the 1850's (Tx-540; R, 1970, v 12, p 249). Deviations reported are based on counting statistics of sample, background, and modern, and are ±1σ, except that when sample count approaches either modern or background, 2σ limits are reported. Unless noted, 12C/13C measurements were not made and results are not corrected for 13C fractionation. Our laboratory uses liquid scintillation counting of benzene, with Li2C2 and vanadium-activated catalyst in preparation; chemical yields range between 95% and 99%. Three counters are employed: a Packard Tri-Carb Model 3002 and 2 Beckman LS320 spectrometers obtained through a grant from the National Science Foundation.

scholarly journals Rudjer Bošković Institute Radiocarbon Measurements X

Radiocarbon ◽  
1987 ◽  
Vol 29 (1) ◽  
pp. 135-147 ◽  
Author(s):  
Dušan Srdoč ◽  
Bogomil Obelić ◽  
Adela Sliepčević ◽  
Ines Krajcar Bronić ◽  
Nada Horvatinčić
Keyword(s):  
Oxalic Acid ◽  
Half Life ◽  
Sample Pretreatment ◽  
Radiocarbon Date ◽  
New Techniques ◽  
Counting Technique ◽  
Modern Standard

The following radiocarbon date list contains dates of samples measured since our previous list (R, 1984, v 26, no. 3, p 449–460). As before, age calculations are based on the Libby half-life (5570 ± 30) yr and reported in years before 1950. The modern standard is 0.95 of the NBS oxalic acid activity. Sample pretreatment, combustion and counting technique are essentially the same as described in R, 1971, v 13, no. 1, p 135–140, supplemented by new techniques for groundwater processing (R, 1979, v 21, no. 1, p 131–137).

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