scholarly journals University of Tokyo Radiocarbon Measurements III

Radiocarbon ◽  
1971 ◽  
Vol 13 (1) ◽  
pp. 94-96 ◽  
Author(s):  
Jun Sato ◽  
Tomoko Sato ◽  
Yasuko Matsui ◽  
Hisashi Suzuki
Keyword(s):  
Oxalic Acid ◽  
Proportional Counter ◽  
Half Life ◽  
Counting Rate ◽  
Modern Standard

Radiocarbon measurements in this list were made from Sept. to Dec., 1968. They are based on acetylene counting in an Oeschger-Houtermans-type proportional counter (1 L) at pressure 1 atm. All data are based on duplicated measurements. For calculation of ages, 95% activity of NBS oxalic acid is used as the modern standard and value of 5570 + 30 years is used for the half-life of C14. Dates are expressed in years B.P. (before A.D. 1950). Error corresponds to 1σ deviation of sample net counting rate as well as modern standard and background. Details of procedures are given in previous reports (R., 1968, v. 10, p. 144–148; 1969, v. 11, p. 509–514)

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 Kiel Radiocarbon Measurements VII

Radiocarbon ◽  
1973 ◽  
Vol 15 (1) ◽  
pp. 113-126 ◽  
Author(s):  
H. Erlenkeuser ◽  
H. Willkomm
Keyword(s):  
Oxalic Acid ◽  
Half Life ◽  
Counting Rate ◽  
Background Sample ◽  
Organic Fractions ◽  
Modern Standard

This list contains data obtained during 1971. Unless otherwise stated, all organic samples or organic fractions are carefully washed with dil. HCl and dil. NaOH to remove all carbonates. Age calculations are based on 95% of NBS oxalic acid standard activity with modern value A.D. 1950. Results are calculated using the Libby half-life and are given in the B.P. scale. Also ages of shells are calculated with the NBS oxalic acid standard. Ages are not corrected for δC13 variations. Errors correspond to Iσ variation of sample net counting rate including statistics of modern standard and background. Sample activities, if given in per cent refer to 0.95 NBS oxalic acid standard activity.

scholarly journals Louvain Natural Radiocarbon Measurements IV

Radiocarbon ◽  
1966 ◽  
Vol 8 ◽  
pp. 248-255 ◽  
Author(s):  
E. Gilot ◽  
N. Ancion ◽  
P. C. Capron
Keyword(s):  
Oxalic Acid ◽  
Tree Rings ◽  
Proportional Counter ◽  
Half Life ◽  
Experimental Error ◽  
The One ◽  
Contemporary Standard ◽  
Modern Standard

The following list covers most of the samples measured at the Louvain C14 laboratory since the last list (Louvain III).The method is essentially the same as the one used for the work described in the previous lists. A CH4 proportional counter, 0.6 L volume, operating at 3 atm pressure, is used. Equipment and counting techniques have been described in Louvain I. Dates are computed on the basis of the Libby half-life, 5570 yr, and the zero of the age scale is A.D. 1950. Ages are quoted with 1σ experimental error, which includes the counting variations of the sample as well as that of the background and the contemporary standard. As modern standard we now use NBS oxalic-acid standard or wood taken from A.D. 1870 to A.D. 1900 tree rings. No differences between the two standards have been observed.

scholarly journals Rudjer Bošković Institute Radiocarbon Measurements II

Radiocarbon ◽  
1973 ◽  
Vol 15 (2) ◽  
pp. 435-441 ◽  
Author(s):  
Dušan Srdoč ◽  
Adela Sliepčevic ◽  
Josip Planinic ◽  
Bogomil Obelic ◽  
Branko Breyer
Keyword(s):  
Oxalic Acid ◽  
Petroleum Coke ◽  
Half Life ◽  
Counting Rate ◽  
Mean Value ◽  
Background Count ◽  
The Mean ◽  
Modern Standard

The present list contains dates of samples measured since our previous list (R., 1971, v. 13, p. 135–140). As before, age calculations are based on the Libby half-life 5568 ± 30 yr, and reported in years before 1950. The modern standard is 0.950 of the activity of NBS oxalic acid, giving a net counting rate of 21.68cpm. The background count is measured by a series of inactive samples such as marble, anthracite, petroleum coke, and old natural methane. Background count of these samples give a mean value of 6.05cpm. It is observed that marble always gives the highest value of background count while natural methane gives the lowest. Results, however, are within ± 1 σ of the mean value.

scholarly journals Gif Natural Radiocarbon Measurements VII

Radiocarbon ◽  
1972 ◽  
Vol 14 (2) ◽  
pp. 280-320 ◽  
Author(s):  
G. Delibrias ◽  
M. T. Guillier ◽  
J. Labeyrie
Keyword(s):  
Stainless Steel ◽  
Oxalic Acid ◽  
Proportional Counter ◽  
Half Life ◽  
Ofhc Copper ◽  
Geologic Samples ◽  
Modern Standard

C14 dates reported below were obtained mainly at the end of 1968 and during 1969 on archaeologic and geologic samples. Techniques of measurement used are unchanged. Since 1968, 4 complete routine sets have been running, each equipped with a 1 L CO2 proportional counter. One is made of stainless steel with a background of 2.70 cpm at pressure 1 atm and the others are of OFHC copper with a background of either 1.10 or 1.30 cpm for a corresponding pressure of, respectively, 1 or 2 atm. For age calculation, 95% activity of NBS oxalic acid is used as the modern standard and the value of 5570 ± 30 years is used for the half-life of C14. Dates are expressed in years b.p. (before a.d. 1950).

scholarly journals Rudjer Bošković Institute Radiocarbon Measurements IX

Radiocarbon ◽  
1987 ◽  
Vol 29 (1) ◽  
pp. 115-134 ◽  
Author(s):  
Dušan Srdoč ◽  
Nada Horvatinčić ◽  
Bogomil Obelić ◽  
Ines Krajcar Bronić ◽  
Adela Sliepčević
Keyword(s):  
Oxalic Acid ◽  
Lake Sediments ◽  
Half Life ◽  
Counting Rate ◽  
Statistical Processing ◽  
Sample Pretreatment ◽  
Initial Activity ◽  
New Techniques ◽  
Plitvice Lakes ◽  
Modern Standard

The following radiocarbon date list contains dates of samples from Plitvice Lakes measured since our previous list dealing with tufa from this region (Srdoč et al, 1982). Tufa measurements from the Knin area in S Croatia and some localities in Bosnia are also listed. Age calculations are based on the Libby half-life (5570 ± 30) yr and reported in years before 1950. Reported ages are based on the initial activity of 85% except for lake sediments where calculations of initial activity have been performed. The modern standard is 0.95 of the NBS oxalic acid activity. Sample pretreatment 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). Statistical processing of data has been computerized (Obelić & Planinić, 1977; Obelić, 1980). The errors quoted correspond to 1 σ variation of sample net counting rate and do not include the uncertainty in 14C half-life.

scholarly journals University of Tokyo Radiocarbon Measurements II

Radiocarbon ◽  
1969 ◽  
Vol 11 (2) ◽  
pp. 509-514 ◽  
Author(s):  
Jun Sato ◽  
Tomoko Sato ◽  
Yasuko Otomori ◽  
Hisashi Suzuki
Keyword(s):  
Oxalic Acid ◽  
Proportional Counter ◽  
Half Life ◽  
Measuring System ◽  
Modern Standard

Radiocarbon measurements in the list below were made during the period from Sept. 1967 to Aug. 1968. Our measuring system is based on acetylene counting in an Oeschger-Houtermans-type proportional counter (1 L) at a pressure of I atm. All data are based on duplicated measurements. For calculation of ages, 95% activity of NBS oxalic acid is used as the modern standard and the value of 5570 ± 30 years is used for the half-life of C14. Details of procedures are given in the previous report (Radiocarbon, 1968, v. 10, p. 144-148).

scholarly journals University of Kiel Radiocarbon Measurements IV

Radiocarbon ◽  
1969 ◽  
Vol 11 (2) ◽  
pp. 423-429 ◽  
Author(s):  
H. Willkomm ◽  
H. Erlenkeuser
Keyword(s):  
Oxalic Acid ◽  
Half Life ◽  
Counting Rate ◽  
Isotopic Fractionation ◽  
Modern Standard

The following dates are samples measured since publication of Kiel III (Radiocarbon, v. 10, p. 328–332). Age calculations are based on 95% of the activity of NBS oxalic-acid standard as modern value of A.D. 1950. Results are calculated with Libby half-life and reported in yr before 1950. Error corresponds to 1σ variation of sample net counting rate as well as modern standard and background, but does not include the uncertainty in C14 half-life and in secular C14 variations. Dates are not corrected for isotopic fractionation.

scholarly journals Nancy Natural Radiocarbon Measurements II

Radiocarbon ◽  
1969 ◽  
Vol 11 (2) ◽  
pp. 463-468 ◽  
Author(s):  
B. Hassko ◽  
B. Guillet ◽  
R. Coppens
Keyword(s):  
Oxalic Acid ◽  
Proportional Counter ◽  
Half Life ◽  
Counting Technique ◽  
Dating Method ◽  
Made In ◽  
Modern Standard

The following list includes a selected number of measurements made during 1967-1968 in the Natural Radiocarbon Laboratory of the Centre de Recherches Radiogéologiques de Nancy. This list is a continuation of Nancy Natural Radiocarbon Measurements I (Radiocarbon, 1968, v. 10, p. 119-123). The dating method, counting technique, and equipment are described in that list. All measurements were made in a proportional counter with a capacity of 1.16 L, normally filled with CO2 under a pressure of 736 mm Hg. Ages are calculated using a C14 half-life of 5568 yrs with 1950 as reference yr. Modern standard used following samples Ny-118 is 95% of NBS oxalic acid activity. The SC14 mentioned later in the date list are calculated according to Broecker and Olson (1959).

scholarly journals University of Kiel Radiocarbon Measurements VI

Radiocarbon ◽  
1971 ◽  
Vol 13 (2) ◽  
pp. 325-339
Author(s):  
H. Erlenkeuser ◽  
H. Willkomm
Keyword(s):  
Oxalic Acid ◽  
Half Life ◽  
Counting Rate ◽  
Modern Standard

This list contains data obtained during 1970. Age calculations are based on 95% of NBS oxalic acid standard activity with modern value A.D. 1950. Results are calculated using the Libby half-life and are given in the B.P. scale. They are not corrected for δC13 variations. Errors correspond to 1σ variation of sample net counting rate including statistics of modern standard and background.

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