Energy levels of A = 21−44 nuclei (V)

https://www.cns.s.u-tokyo.ac.jp/~shimoura/research/nuc_data/pdf/11.pdf

Energy levels of light nuclei A = 11-12

Fusion and breakup of weakly bound nuclei

Energy levels of light nuclei A = 16-17

Energy levels of light nuclei A = 18–19☆

We discus here the prehistoric settlement of the central-south Brazilian coast, and, more specifically, 1 old radiocarbon date obtained for a coastal shellmound, as well as its implications concerning the chronology attributed to the settlement process. The accelerator mass spectrometry (AMS) technique was used to determine the (super 14) C age of charcoal from a shellmound on the southern coast of Rio de Janeiro. The resulting age was 7860+ or -80 BP, an unexpected result that reinforces 2 similar previously obtained dates for the same region. Brazilian archaeologists, however, have questioned those 2 dates, because they would predate by some 2000 yr the antiquity consensually accepted for the settlement of the central-south Brazilian littoral.

/pdf/the-antiquity-of-the-prehistoric-settlement-of-the-central-2rhg9jvhug.pdf

The antiquity of the prehistoric settlement of the central-south Brazilian coast

The monoenergetic gamma-ray attenuation methodology is applied to study the structure of two well-aggregated Brazilian soils. The methodology distinguishes pores that comprise the space between aggregates and pores present only within aggregates. A comparison of the results with those obtained by conventional methodologies, indicates very good agreement. It is concluded that the methodology is very convenient to monitor the spatial distribution of inter- and intra-aggregate porosities since it is a nondestructive methodology and allows the evaluation of porosity changes that may occur during long periods of soil cultivation. Once having obtained a calibration regression for a given soil layer, total intra- and inter-aggregate porosities can be obtained from soil bulk density data only.

Soil structure evaluated by gamma-ray attenuation

This paper discusses the chronology of prehistoric settlements of the central-south Brazilian coast. A charcoal sample from a coastal shellmound of Rio de Janeiro State was dated by 14C-AMS to 7; 860§ 80 years BP as part of an interdisciplinary project between physicists and archaeologists. This is an unexpected result that reinforces two similar previous early dates for the same region, which were questioned by Brazilian archaeologists because they implied in pulling back by some two thousand years the antiquity consensually accepted for the settlement of that region.

/pdf/ams-dating-of-early-shellmounds-of-the-southeastern-4dnhx3ibue.pdf

AMS dating of early shellmounds of the southeastern Brazilian coast

The in-beam and off-beam gamma-ray spectroscopy method, as a tool for the study of nuclear fusion between heavy ions, is described. These methods allow the study of the production and decay of the compound nucleus, inelastic scattering and transfer reactions. In this work we report the determination of fusion cross sections at energies near and below the Coulomb barrier for a series of systems: targets of 46,50 Ti, 59 Co and 64,66 Zn bombarded by 14 N and 16 O projectiles. Cross sections from 0.4 to 1000 mb were measured.

Nuclear fusion between heavy ions by the gamma-ray spectroscopy method

This paper presents a new date for one of the oldest shellmounds of the central-south Brazilian coast. This date seems to confirm three previous results obtained from two other shellmounds in the same region and formerly seen as unreliable by the archaeological community. A charcoal sample from a coastal shellmound located in the state of Rio de Janeiro, Sambaqui do Algodao, was dated by 14C-AMS to 7860 ± 80 years BP. Besides confirming the previous ones, this new date is pulling back by some two thousand years the consensually accepted antiquity for the initial settlement of the central-south Brazilian coast – around 6000 years BP. The geographical and chronological proximity of those archaeological sites suggest that the initial settlement of the coast would have begun in this region rather than in the nuclear area with denser concentrations of shellmounds further to the South. It also strengthens the evidence of the possible route used by inland hunter-gatherers to reach this part of the coast.

M M Coimbra

Papers

The antiquity of the prehistoric settlement of the central-south Brazilian coast

Soil structure evaluated by gamma-ray attenuation

AMS dating of early shellmounds of the southeastern Brazilian coast

Nuclear fusion between heavy ions by the gamma-ray spectroscopy method

The earliest shellmounds of the central-south Brazilian coast