{"status":"OK","msg":"Details loaded!","speaker":{"id":10,"speaker":"Cristina V\u00e1zquez","sarx_lecture":"Evolution of TXRF in Latin America countries","sarx_lecture_abstract":"In 1923, Arthur Compton discovered the phenomenon of total reflection of X-rays. He found that the reflectivity of a flat target strongly increased bellow a critical angle of only 0,1o. Fifty years later, in 1971, Yoneda and Horiuchi first took advantage to this effect. They proposed the analysis of a small amount of material deposited on a flat totally reflecting support. This idea was subsequently implemented in the so-called total reflection X-ray fluorescence (TXRF) analysis which has spread out worldwide. Nowadays, TXRF is a recognized analytical tool with high sensitivity and low detection limits, down to the femtogram range. It is being used in geology, biology, materials science, medicine, forensics, archeology, art history, and more. In this presentation a summary of how the TXRF reaches Latin America countries is presented.","earj_lecture":"Portable RAMAN for in situ analysis of pigments","earj_lecture_abstract":"Raman measurements provides advantages over others analytical instrumental methods considering it does not require sample pre-treatment performing the analysis on direct contact with the sample. The development of handheld Raman spectrometers has drastically changed the way the archaeometrics conducts research in order to simplify, protect and facilitated the analysis of cultural heritage, especially for murals and rock paintings.The aim of this presentation is to show the use of portable Raman for the investigation of pigment composition, the raw materials and supply sources used by the ancient inhabitants in Northpatagonia, Argentina, in their own environment. This project was organized as a measurement campaign in order to study rock art paintings, in situ. To identify compounds and pigments, as well as degradation products of the rock, it was used a portable Raman. This equipment has recently been used to study rock art in Spain, France and South Africa. While fixed equipment are not new, so far, analysis by a portable Raman has not been reported even in Northpatagonia. This means that it is not necessary, in the latter case, to extract a piece of sample for analysis, resulting in a nondestructive and simple technique to implement in place.\r\nThe research focuses on the identification of different materials used in order to account for some possible temporal and \/ or spatial relationships. The distinction between possible colored clay and crushed rocks, especially the effect of painting on rock substrates, provide valuable information on manufacturing techniques and production processes developed by hunter-gatherers in the area. It could also determine the local \"palette\" of the natives. \r\nThe study was conducted in three different areas:\r\n1. Sites at Traful area, the shelters: Los Cipreses, Las Mellizas and R\u00edo Blanco (Aldaz\u00e1bal, 2007, 2014; Silveira, 2013);\r\n2. Sites at Valle Encantado (Maqui shelter, del Ocho cave)\r\n3. Near San Carlos de Bariloche, the shelters: Queutrei Malef, Los R\u00e1pidosr; Moreno Laker, El Tr\u00e9bol and Cerro Campanario (Albornoz, 2000).\r\nIn a first stage, Raman measurements were conducted by scientists at the University of Ghent, Belgium (Rousaki, 2015). In a second stage, the technical results will be interpreted in context, in an interdisciplinary way, by Argentinean archaeologists involved in these areas. Complementarily, information on material degradation processes by the environment will provide the knowledge for better conservation and preservation of the paintings.","country":"Argentina","institution":"University of Buenos Aires (Argentina)","earj":1,"sarx":1,"duration":30,"short_bio":"","cvlink":"https:\/\/drive.google.com\/open?id=0B5OeqF_9a9c3enJxeHdhNXZ0dXM","picture":"http:\/\/sarx2016.nbcgib.uesc.br\/speaker\/10\/picture","email":"vazquezcristi@gmail.com","cvfile":null,"created_at":"-0001-11-30 00:00:00","updated_at":"2016-08-22 17:00:13","lecture":"Evolution of TXRF in Latin America countries","abstract":"In 1923, Arthur Compton discovered the phenomenon of total reflection of X-rays. He found that the reflectivity of a flat target strongly increased bellow a critical angle of only 0,1o. Fifty years later, in 1971, Yoneda and Horiuchi first took advantage to this effect. They proposed the analysis of a small amount of material deposited on a flat totally reflecting support. This idea was subsequently implemented in the so-called total reflection X-ray fluorescence (TXRF) analysis which has spread out worldwide. Nowadays, TXRF is a recognized analytical tool with high sensitivity and low detection limits, down to the femtogram range. It is being used in geology, biology, materials science, medicine, forensics, archeology, art history, and more. In this presentation a summary of how the TXRF reaches Latin America countries is presented."}}