MARESIAS 4th Internacional Nuclear Chemistry 2014
Transcription
MARESIAS 4th Internacional Nuclear Chemistry 2014
4th INTERNATIONAL NUCLEAR CHEMISTRY CONGRESS . RADIOGRAPHY APLLIED TO FUNERAL AND UTILITY ARCHAEOLOGICAL CERAMICS STUDIES Alfredo V. B. Bellido and Rose Mary Latini – UFF Maria Inês S. SOUZA and Gevaldo L. ALMEIDA – IEN/CNEN Introduction • We have been studding this archaeological sites for a long time, ceramics from the Brazilian Amazon, specifically the Purus River basin, in the state of Acre and the Lakes region in the state of Rio de Janeiro, Brazil. • This allowed us to know the potential of different physical and chemical techniques methodologies for the characterization, classification, provenance studies and dating this ceramics (Potsherds) – INAA, Mössbauer spectroscopy , TL all combined with MVSA . Study Area in State of Acre The potteries discovered in these archaeological sites were preclassified by archaeologists, in three archaeological phases denominated as Quinari, Iquiri and Iaco. Other fragments from Los Angeles Archaeological Site don´t belong to any defined archaeological phases. The Acre region has archaeological sites with and without earth circular structures. Potsherds Study area the Lakes Region state of Rio de Janeiro OBJECTIVE: The aim of this study is to investigate manufacturing techniques used in prehistoric Brazilian pottery from Amazon Basin in the state of Acre and the Lakes Region state of Rio de Janeiro using Gama Ray Radiography Manufacturing Techniques – Preparation of Ceramics • T h e m a i n d i f f e r e n c e s i n t h e m a n u a l manufacturing techniques of ceramics are related to the way the clay was handled. Two such techniques are a roller and pallet [1]. • Palette technique exhibits a homogeneous mass and the rollers technique exhibits horizontal traces from the junction of rollers, overlapping, forming layers supported on each other and smoothed to obtain a homogeneous surface. Difference between the manufacturing techniques - palette and rollers Test objects CP1- rollers with coverage; CP2 - rollers without coverage; CP3 - rollers with little cover and CP4 - palette. Original Image Image correcteddiverging beam to simulate a parallel beam- by the algorithm embedded in the PlotXP software The attenuation map, expressed by the pixel intensity. The brighter strips correspond to the dichtes separating the rollers in CP1 (Rolls) but not in CP4 (Pallets). Surface plot of the corrected image with the PlotXP – and original image. Experimental Arrangement • Source of γ-rays - 165Dy (95 keV) was produced at IEN/CNEN • Exposure time – 2 hours • Detector: Imaging Plate. UTILITY CERAMICS FUNERAL CERAMICS Neutrongraphy Other Thechniques ARRANJO DE MODERAÇÃO E COLIMAÇÃO INSERIDA NO CANAL PARA OBTENÇÃO DAS IMAGENS Potteries fragments on the image plate. Características neutrônicas na saída do canal onde os tomógrafos são instalados P=340W Fluxo térmico fluxo epitérmico razão de cádmio razão L/D razão n/ 4.46 x 105 n.cm-2 s-1 6,0 x 103 n.cm-2 s-1 25 63,25 3,00 x 106 n.cm-2.mR-1 The Neutrongraphy shows two different manufacturing details: (a) rollers and (b) palette Microtomography Technique • Radiography and µ–CT have been used to identify manufacturing details. The radiography represents a superposition of all layers of the object in the beam direction. Differentiation between front and back of the inside contents is not possible. In this way µ–CT was applied for the visualisation of cavities, differences in manufacture of pore orientation structures and differences in temper. Equipment: µCT SkyScan/Bruker, model 1173 • The experimental conditions were 90 kV, 80 µA with image pixel size of 15µm. The exposure time was 1300 ms and the rotation step was 0.5 degrees within a 360º, which led a total acquisition time of 01h20min. It was used a bench-top µCT SkyScan/Bruker, model 1173. Archaeological Phases, Acre Brazil Temper Iquiri Los Angeles Iaco Quinari TEST OBJECTS AND MICROTOMOGRAPHY IMAGES PALETTE TECHNIQUE ROLLER TECHNIQUE CONCLUSIONS • This work has evaluated the feasibility to identify the type of technique employed in the ceramics manufacturing - whether rollers or pallets and the classification of the Archaeological Phases specially that used in prehistoric Brazilian pottery from Acre state. • The results show the potentiality of these techniques for studies of manufacturing details and this information may contribute to a better understanding of the archaeological classification and provenance studies. REFERENCES 1. 2. 3. 4. 5. 6. 7. 8. A Lindahl and I. Pikirayyi. Ceramics and change: an overview of pottery production techniques in northern South Africa and eastern Zimbabwe during the first and second millennium. Archaeol Anthropol Sci, 2:133–149, 2010. R.M. Latini, A.V. Bellido, U. M. Vinagre Filho, M. I. S. Souza, I. Lima, D.F. Oliveira and R.T.Lopes, Archaeometric studies by neutron, x-ray radiography and microCT. AIP Conf. Proc. 1529, 49, 2013. G. L. Almeida, M. I. Silvani, An Algorithm to unveil the Inner Structure of Objects concealed by Beam Divergence in Radiographic Image Acquisition Systems. XXXVI Reunião de Trabalho sobre Física Nuclear no Brasil, September 01-05, 2013. Maresias - SP, Brazil. M. I. Silvani, G. L. Almeida, Enhancing the Quality of Radiographic Images acquired with Point-like gamma-Ray Sources through correction of the Beam Divergence and Attenuation. XXXVI Reunião deTrabalho sobre Física Nuclear no Brasil, September 01-05, 2013. Maresias - SP, Brazil. R.M Latini, A.V.B.Bellido, O.F. Dias Junior, L.F.Bellido. “Determining the Provenience of Prehistoric Ceramic Artefacts from the Amazon Basin Using Geochemical Tracers”. In Environmental Geochemistry inTropical and Subtropical Environments, Lacerda LD, Santelli R, Duursma E, Abrão J. (eds). Springer-Verlag:Heidelberg, 2004; 93-99. U. M Vinagre Filho, A.V.B.Bellido; R.M Latini, A. Buarque, A.M. Borges. “Estudos de Proveniência emCerâmicas Arqueológicas Unas do Rio de Janeiro” In: XXXI Reunião de Trabalho sobre Física Nuclear no Brasil, São Sebastião/SP. 2008. A.V.B.Bellido, R.M Latini, I. G. Nícoli R. Scorzelli, P.M. Solorzano. “Neutron Activation Analysis and Mössbauer Correlations of Archaeological Pottery from Amazon Basin for Classification Studies”. XXXIII BRAZILIAN WORKSHOP ON NUCLEAR PHYSICS, AIP Conference Proceedings, v.1351, p.288 – 292,2011. P.M. Solorzano, R. Scorzelli, R.M Latini, A.V.B.Bellido. “Estudo de Ceramicas Arqueologicas da Bacia Amazônica”. IX Congresso Ibérico de Arqueologia. Lisboa, 2011. Thank you for your attention Muito obrigado pela atenção alfredobellido@gmail.com