Teodoro Rivas

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HE agricultural sector has always been an important component of the Dominican Republic’s economy. During the 1980s, agriculture accounted for as much as 20 per cent of the gross domestic product (GDP), 45 per cent of overall employment, and over 50 per cent of total foreign exchange earnings. By contrast, during this period the manufacturing sector(More)
We describe the results of sulphur and oxygen isotope analyses used to identify sources of the gypsum present in black crusts that grow on the granite of historical buildings. The crusts were sampled at various locations in and near the city of Vigo (NW Spain) and were analysed for their sulphur content and δ(34)S and δ(18)O isotope ratios. Sampled crusts(More)
Marking petroglyphs with chalk is a common practice to enhance them for documentation and reproduction. Although this procedure has started to be less frequently used, there is no knowledge about the interaction between the rock engravings nor about the effectiveness achieved by the common cleaning procedures of such markers considering the chalk extraction(More)
Most of the Cultural Heritage built in NW Iberian Peninsula is made of granite which exposition to the environment leads to the formation of deposits and coatings, mainly two types: biological colonization and sulphated black crusts. Nowadays, another form of alteration derives from graffiti paints when these are applied as an act of vandalism. A deep(More)
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