scholarly journals Quality Controlled Radiocarbon Dating of Bones and Charcoal from the Early Pre-Pottery Neolithic B (PPNB) of Motza (Israel)

Radiocarbon ◽  
2005 ◽  
Vol 47 (2) ◽  
pp. 193-206 ◽  
Author(s):  
Meirav Yizhaq ◽  
Genia Mintz ◽  
Illit Cohen ◽  
Hamudi Khalaily ◽  
Steve Weiner ◽  
...  

Radiocarbon dating of early Pre-Pottery Neolithic B (PPNB) deposits at the site of Motza, Israel, was achieved by first prescreening many charcoal and bone samples in order to identify those that are in the most suitable state of preservation for dating. For assessing bone preservation, we determined the collagen contents, and by infrared spectroscopy the collagen purity. The collagen samples of the best preserved bones were then further characterized by their C/N ratios and amino acid compositions. Prescreening of the charcoal samples involved monitoring the changes in infrared and Raman spectra during the acid-alkali-acid treatments. In some samples, we noted that the clay content increased with additional alkali treatments. These samples were rejected, as this could result in erroneous dates. No differences were observed in the 14C dates between charcoal and bone collagen samples. The dates range from 10,600–10,100 cal BP, which is consistent with dates for the early PPNB from other sites. This is of much interest in terms of better understanding where and when domestication of animals began in this period, and how agriculture spread throughout the Levant.

1985 ◽  
Vol 63 (9) ◽  
pp. 2411-2419 ◽  
Author(s):  
Helen Elaine Howard-Lock ◽  
Colin James Lyne Lock ◽  
Philip Stuart Smalley

The X-ray crystal structure of (S)-2,2,5,5-tetramethylthiazolidine-4-carboxylic acid, 1, has been determined. Crystals are monoclinic, P21, with cell dimensions a = 11.351(4) b = 8.303(2), c = 11.969(3) Å, β = 116.69(2)°, and Z = 4. The structure was solved by standard methods and refined to R1 = 0.0774, R2 = 0.0670 for 2388 independent reflections. Compound 1 exists in the amino-acid form as shown by two distinctly different C—O bond lengths, 1.209 and 1.309 Å, typical of the COOH group, and by the positions of the hydrogen atoms. The amino-acid form of 1 found in the solid also exists in solution as shown by infrared and Raman spectra. The mass spectra, and 1H and 13C nmr spectra are reported, as well as detailed infrared and Raman spectra for the title compound and several deuterated species.


Radiocarbon ◽  
2013 ◽  
Vol 55 (3) ◽  
pp. 1443-1453 ◽  
Author(s):  
Stuart J Fiedel ◽  
John R Southon ◽  
R E Taylor ◽  
Yaroslav V Kuzmin ◽  
Martin Street ◽  
...  

Four accelerator mass spectrometry (AMS) facilities undertook an interlaboratory exercise designed to examine the reliability and reproducibility of radiocarbon determinations on bone by dating a sample of elk (Alces alces) from Miesenheim IV. This specimen is derived from a secure geological context directly beneath the Laacher See tephra, which provides a precise terminus ante quern of ∼11,060 yr BP (∼13,050 cal yr BP). Regrettably, the results of the intercomparison exercise were complicated by evident contamination of the bone sample by exogenous organic material. This contaminant, probably humic acid, resulted in a wide span of ages (10,010 ± 30 to 11,100 ± 45 BP). The only method that yielded an accurate determination, consistent with the age of the tephra, was Oxford's single amino acid technique, which targets hydroxyproline. An acid hydrolysis step seems to have been crucial in breaking the bonds between the bone collagen and the contaminant.


1977 ◽  
Vol 30 (3) ◽  
pp. 669 ◽  
Author(s):  
AJ Canty ◽  
R Kishimoto

The preparation and characterization of phenylmercury(II) complexes of L-cysteine and DL-penicillamine are reported. Infrared and Raman spectra of the new complex μ-cysteinato-S,N-bis[phenylmercury(n)] monohydrate and of previously reported complexes of L-cysteine and DL- penicillamine are compared. The complexes decompose to form diphenylmercury when stirred as suspensions in benzene at ambient temperature.


1995 ◽  
Vol 6 (3) ◽  
pp. 34-37
Author(s):  
Shinobu Fujihara ◽  
Atsuko Kasuga ◽  
Tatsuyuki Sugahara ◽  
Yasuo Aoyagi

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