31 resultados para COLLECTION OF EXTRATERRESTRIAL PARTICLES FROM STRATOSPHERE


Relevância:

100.00% 100.00%

Publicador:

Resumo:

Dissertação apresentada na Faculdade de Ciências e Tecnologia da Universidade Nova de Lisboa para a obtenção do grau de Mestre em Engenharia do Ambiente,perfil Sanitária

Relevância:

100.00% 100.00%

Publicador:

Resumo:

International Journal of Architectural Heritage, 8: 185–212, 2014

Relevância:

100.00% 100.00%

Publicador:

Resumo:

This work presents the archaeometallurgical study of a group of metallic artefacts found in Moinhos de Golas site, Vila Real (North of Portugal), that can generically be attributed to Proto-history (1st millennium BC, Late Bronze Age and Iron Age). The collection is composed by 35 objects: weapons, ornaments and tools, and others of difficult classification, as rings, bars and one small thin bent sheet. Some of the objects can typologically be attributed to Late Bronze Age, others are of more difficult specific attribution. The archaeometallurgical study involved x-ray digital radiography, elemental analysis by micro-energy dispersive X-ray fluorescence spectrometry and scanning electron microscopy with energy dispersive spectroscopy, microstructural observations by optical microscopy and scanning electron microscopy. The radiographic images revealed structural heterogeneities frequently related with the degradation of some artefacts and the elemental analysis showed that the majority of the artefacts was produced in a binary bronze alloy (Cu-Sn) (73%), being others produced in copper (15%) and three artefacts in brass (Cu-Zn(-Sn-Pb)). Among each type of alloy there’s certain variability in the composition and in the type of inclusions. The microstructural observations revealed that the majority of the artefacts suffered cycles of thermo-mechanical processing after casting. The diversity of metals/alloys identified was a discovery of great interest, specifically due to the presence of brasses. Their presence can be interpreted as importations related to the circulation of exogenous products during the Proto-history and/or to the deposition of materials during different moments at the site, from the transition of Late Bronze Age/Early Iron Age (Orientalizing period) onwards, as during the Roman period.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Biophysical Chemistry 110 (2004) 83–92

Relevância:

100.00% 100.00%

Publicador:

Resumo:

The Middle and Upper Jurassique limestones investigated were sub-divided into nine microfacies (MF) types. The firsts four represent Bathonian sediments with shallow water characteristics typical for carbonate platforms. They are comparable with Wilson's facies zones 6 to 8. Reef and reef debris, near-shore clastic-dominated limestones are not present. These MF-types are reiterated several times without cyclicity. The vertical development of the differentiated facies units indicates a close interfingering. The microfacies data are typical of inter to shallow subtidal environments; both authigenous quartz and low faunal and floral diversity of several layers point to temporary restricted conditions. The occurrence of Dictyoconus cayeuxi LUCAS and Callovian ammonites from the above lying strata argue for a Bathonian age. The MF-types 5-9 (Oxfordian-Kimmeridgian) show completely different sedimentation conditions. Fully marine nearshore recifal limestones alternate with pelagic sediments formed at deeper shelf areas. The pelagic micritic limestones of Oxfordian age are characterized by allodapic intercalations whereas the Oxfordian/Kimmeridgian limestones with tuberolithic fabrics often show intensive silifications. Only initial patch reef growth-stages were reached during the development of the Oxfordian and Kimmeridgian shallow water limestones.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Dissertation presented in partial fulfillment of the requirements for the degree of Master in Biotechnology

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Dissertation submitted in partial fulfilment of the requirements for the Degree of Master of Science in Geospatial Technologies

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Thesis submitted to the Instituto Superior de Estatística e Gestão de Informação da Universidade Nova de Lisboa in partial fulfillment of the requirements for the Degree of Doctor of Philosophy in Information Management – Geographic Information Systems

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Dissertação apresentada na Faculdade de Ciências e Tecnologia da Universidade Nova de Lisboa para obtenção do grau de Mestre em Conservação e Restauro

Relevância:

100.00% 100.00%

Publicador:

Resumo:

International Biodeterioration & Biodegradation,xxx (2009) 1–8

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Siliceous rocks are widely used as dimension stone but the last decades have registered an increase rate of their alteration when exposed to polluted environments. Anorthosites were treated by acidified solutions of HCl, HN03 and H2S04 simulating acid rain and the response was recorded through different experiments such as on the surface of the polished rock and on the surface of uncovered thin sections. The main components, plagioclase and olivine, both responded in similar ways to each acid solution, although following different trends; while plagioclase develops a thin layer which acts as protection to the mineral, olivine at first undergoes alteration due to leaching of magnesium and iron and in a following stage, is mechanically removed from the rock. The action of warm water on the rock was tested through the use of the Soxhlet extractor which caused changes on the rock colour and leaching of several cations from its components.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Dissertation Presented to obtain the Ph.D. in Biochemistry

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Dissertação para a obtenção de grau de doutor em Bioquímica pelo Instituto de Tecnologia Química e Biológica da Universidade Nova de Lisboa

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Dissertação apresentada para obtenção do Grau de Doutor em Engenharia Química e Bioquímica pela Universidade Nova de Lisboa, Faculdade de Ciências e Tecnologia

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Dissertação para obtenção do Grau de Doutor em Engenharia Química, especialidade de Engenharia Bioquímica