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 Birmingham University Radiocarbon Dates V

Radiocarbon ◽  
1971 ◽  
Vol 13 (2) ◽  
pp. 141-156 ◽  
Author(s):  
F. W. Shotton ◽  
R. E. G. Williams
Keyword(s):  
Statistical Analysis ◽  
Standard Deviation ◽  
Sample Size ◽  
Half Life ◽  
Background Count ◽  
Radiocarbon Dates

The following list comprises results obtained during 1970 from both the 1 L and 6 L counters. Results are not corrected for C13fractionation. Errors quoted refer only to the standard deviation calculated from a statistical analysis of sample and background count rates and the Libby half-life of 5570 ± 30 yr. Pretreatment has been continued as described previously (R., 1969, v. 11, p. 263). In cases where sample size was insufficient for full pretreatment, details of the necessary deviations accompany the result.

scholarly journals Birmingham University Radiocarbon Dates IV

Radiocarbon ◽  
1970 ◽  
Vol 12 (2) ◽  
pp. 385-399 ◽  
Author(s):  
F. W. Shotton ◽  
D. J. Blundell ◽  
R. E. G. Williams
Keyword(s):  
Statistical Analysis ◽  
Standard Deviation ◽  
Half Life ◽  
Background Count ◽  
Radiocarbon Dates

Measurements have continued with both the 1 L and 6 L counters. Results are not corrected for C13 fractionation. Errors quoted refer only to the standard deviation calculated from a statistical analysis of sample and background count rates and the Libby half-life of 5570 ± 30 yr. Pretreatment has been continued as described previously (Shotton, Blundell, and Williams, 1969).

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 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 Birmingham University Radiocarbon Dates VI

Radiocarbon ◽  
1973 ◽  
Vol 15 (1) ◽  
pp. 1-12 ◽  
Author(s):  
F. W. Shotton ◽  
R. E. G. Williams
Keyword(s):  
Statistical Analysis ◽  
Standard Deviation ◽  
Oxalic Acid ◽  
Sample Size ◽  
Mass Spectrometer ◽  
Half Life ◽  
Radiocarbon Dating ◽  
Radiocarbon Dates

The following list comprises results obtained during 1971 from both the 1 L and 6 L proportional gas counters at pressures of 1 to 3 atm of methane. Age calculations are based on 95% activity of NBS oxalic acid standard and computed from the Libby half-life of 5570 ± 30 yr. Background samples are synthesized from Welsh anthracite. Errors quoted refer only to the standard deviation (1σ) calculated from a statistical analysis of sample, background, and standard count rates. Recently a Micromass 6 mass spectrometer was installed in the Radiocarbon Dating Laboratory which will enable C13 measurements on future samples. Pretreatment is continued as described previously (R., 1969, v. 11, p. 263) but in cases where sample size was insufficient for full pretreatment, details are described.

scholarly journals Birmingham University Radiocarbon Dates VII

Radiocarbon ◽  
1973 ◽  
Vol 15 (3) ◽  
pp. 451-468 ◽  
Author(s):  
F. W. Shotton ◽  
R. E. G. Williams
Keyword(s):  
Statistical Analysis ◽  
Standard Deviation ◽  
Oxalic Acid ◽  
Half Life ◽  
Sample Pretreatment ◽  
Radiocarbon Dates ◽  
Counting Equipment

The following list of dates contains all measurements made during 1972, i.e., since our last list. Counting equipment, operating procedures and sample pretreatment are the same as previously described (R., 1969, v. 11, p. 263). Age calculations are based on 95% activity of the NBS oxalic acid standard computed from the Libby half-life of 5570 ± 30 yr. Background samples are synthesized from Welsh anthracite. Errors quoted refer only to the standard deviation (1σ) calculated from a statistical analysis of sample, background and standard count rates.

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 Vienna Radium Institute Radiocarbon Dates IX

Radiocarbon ◽  
1979 ◽  
Vol 21 (2) ◽  
pp. 298-305
Author(s):  
Heinz Felber
Keyword(s):  
Proportional Counter ◽  
Half Life ◽  
Standard Sample ◽  
Radium Institute ◽  
Radiocarbon Dates ◽  
Standard Deviations ◽  
Single Standard ◽  
Background Counting

Measurements have continued with the same proportional counter system, pretreatment procdure, methane preparation, measurement, and calculation, as described previously (R, 1970, v 12, p 298-318). Uncertainties quoted are single standard deviations originating from standard, sample, background counting rates and half-life. No 13C/12C ratios were measured.

scholarly journals University of Miami Radiocarbon Dates VIII

Radiocarbon ◽  
1977 ◽  
Vol 19 (1) ◽  
pp. 118-126 ◽  
Author(s):  
D Piepgras ◽  
J J Stipp
Keyword(s):  
Standard Deviation ◽  
Half Life ◽  
Radiocarbon Dates ◽  
Partial List ◽  
University Of Miami

The following radiocarbon measurements are a partial list of projects and samples dated since January 1975. The technique used is described in R, v 16, pp 402-408 and R, v 18, pp 210-220. Dates are calculated using 14C half-life of 5568 yr and errors are reported as one-standard deviation.

scholarly journals Vienna Radium Institute Radiocarbon Dates II

Radiocarbon ◽  
1971 ◽  
Vol 13 (1) ◽  
pp. 126-134 ◽  
Author(s):  
Heinz Felber
Keyword(s):  
Proportional Counter ◽  
Half Life ◽  
Sample Pretreatment ◽  
Radium Institute ◽  
Radiocarbon Dates

Measurements have continued with the same proportional counter system, the same procedure in sample pretreatment, methane preparation and measurement, and the same age calculation using a half-life of 5568 ± 30 yr as described previously (R., 1970, v. 12, p. 298–318).

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