IPT - Outras Áreas de Investigação
Permanent URI for this community
Browse
Browsing IPT - Outras Áreas de Investigação by Issue Date
Now showing 1 - 10 of 82
Results Per Page
Sort Options
- Em meses de inverneira, histórias à lareira : Provérbios e dizeres enquanto transmissores de valores culturais e de identidade.Publication . Sol, HermíniaA tradição oral, enquanto objecto passível de ser teorizado e analisado cientificamente, ocupa ainda um espaço muito limitado no meio académico. Numa tentativa de romper com este estado de coisas, este artigo pretende reflectir sobre o papel que os provérbios e dizeres têm na perpetuação de certos valores culturais e nacionais. Para tal irá abordar a natureza didáctica destes dois fenómenos comunicacionais enquanto compromisso com as culturas de onde emergem. À luz do trabalho de Durkheim e de Vansina, irá explorar de que forma é que este género de produções anónimas contribui para a criação e manutenção da memória colectiva de uma dada comunidade. Traçará, também, alguns paralelos entre provérbios nacionais e seus congéneres europeus, no sentido de demonstrar que estes terão servido de veículo para o intercâmbio de ideias. Por último, fará menção a alguns projectos em curso que visam instigar a preservação e transmissão de aspectos do passado através da tradição oral.
- Clays from Vila Nova da Rainha (Portugal): Appraisal of their relevant properties in order to be used in construction ceramicsPublication . Coroado, João; Ferraz, Eduardo; Gomes, Celso F.; Rocha, FernandoThe clay deposit of Vila Nova da Rainha (VNR) is included in the lithostratigraphic forma tion named “Argilas de Tomar”, and is located at the lower section of the Tert iary Tagus’ river basin. Clay from one quarry is being extracted for the production of construction ceramics. In this work the firing transformations undergone by VNR cl ays containing quartz, alkaline feldspar, iron oxy-hydroxides, and clay minerals have been studied. Ca rbonates have not been identified in thes e raw materials. The clay layers can be subdivided in three groups based upon composition and ceramic properties. The first group, VNR0, is represented by smectite-kaolinite sandy-silty clay, the second group (VNR1 and VNR2) corresponds to illite-kaolinite bearing clay and the third group (VNR3 and VNR4) is represented by illite-smectite silty clay. The firing process involves the formation of hematite and mu llite both influencing the technical properties of the fired products. With regards to the ceramic properties assessed at 1100 ºC the first group showed the lowest total shrinkage value (7.35 %) the highest water absorption value (12.2 %) and the lo west mechanical bending strength value (12.0 MPa); the same properties assessed in the second group provi ded the highest firing shrinkage values (7.0-5.0 %), the lowest values of water absorption (0.1-0.2 %) and relatively high mechanical bending strength values (47.8-48.0 MPa); the third group showed firing shrinkage values within the range 3.5-4.2 %, water absorption values within the range 1.4-4.5 %, and the highest mechanical bending strength values (49.2-52.0 MPa). The results of the ceramic properties being appraised indicate that the raw materials being studied are suitable for the production of high-quality construction ceramics, such as brick, roof tile and rustic floor tile.
- Theory vs practice: synthesis of red lead following ancient recipesPublication . Gonçalves, Paula M.; Pires, João; Carvalho, Ana P.; Mendonça, Maria Helena; Cruz, António JoãoThe synthesis of red lead pigment (chemically lead oxide, Pb3O4) was carried out considering different starting lead compounds. The experimental procedure followed was established according to some recipes of ancient painting treatises and the knowledge of the phase transformation of lead oxides. The samples transformation was monitored by X-ray powder diffraction and selected samples were also characterized by scanning electron microscopy. The pure Pb3O4 phase was obtained for the transformation of PbO2 and 2PbCO3·Pb(OH)2. Morphological studies revealed that the material obtained from PbO2 presented the more homogeneous grain size distribution. The transformation of white lead Kremer Pigment resulted in a mixture of Pbr3O4 (major phase) and cerussite (PbCO3), leading to a sample with low crystallinity.
- Sobre um tratado inédito de pintura da primeira metade do século XVII: o 'Breve Tratado de Iluminação', composto por um religioso da Ordem de CristoPublication . Cruz, António João; Monteiro, PatríciaAn anonymous Portuguese manuscript about painting materials and techniques, entitled Breve Tratado de Iluminação, that is, Short Treatise on Illumination, unpublished until now, is presented in detail, as well as its authorship, date, sources, structure and originality. The manuscript, dated from the first half of the 17 th century (after 1618), is a miscellaneous work composed by two main pieces, with the same calligraphy, and varied recipes, with diverse calligraphies, some of them organized around specific subjects. The two main pieces, in a small number of recipes, show the use of Filipe Nunes’ The Art of Painting, a Portuguese treatise published in 1615. In addition, these pieces quote technical procedures employed by both Portuguese and foreigner painters that worked in Portugal, although the sources of this information remain unknown. In relation to the assorted recipes, several were detailed copied from, among others unidentified sources, Nunes’ treatise and Spanish editions of Juan Pérez de Moya (the only work mentioned in the manuscript) and Alessio Piemontese works, both dated from the second half of the 16th century, and others recipes mentioned procedures used by Spanish or French artists. The manuscript, as a whole, seems to be an original work and it is possible that its authors were monks at a Lisbon convent.
- Em busca da origem das cores de 'O Livro de Como se Fazem as Cores': sobre as fontes de um receituário português medieval de materiais e técnicas de pinturaPublication . Cruz, António JoãoO Livro de Como se Fazem as Cores, that is, The Book on How to Make Colours, is a 15th century Portuguese compilation of receipts about painting materials and techniques for which sources and influences were searched. Contrary to the expectations, influences of the Mappae Clavicula were not found, but some similarities were detected between O Livro de Como se Fazem as Cores and Jehan Le Begue treatise’s Experimenta de Coloribus (1431), the H490 Montpellier Manuscript (1460-1480) and, to a lesser degree, thet Bolognese Manuscript also know as Segreti per Colori (first half of the 15i th century). These similarities manifested through the procedures on how to make some pigments, namely mosaic gold and silver blue, and through the names attributed to certain pigments or pigments’ raw materials.
- Breve Tratado de Iluminação composto por um religioso da ordem de CristoPublication . Monteiro, Patrícia; Cruz, António João[fl.1] {1} Breve Tratado de Iluminação composto por hum Religioso da ordem de Cristo repartido em tres partes. 1ª Na primera se declara os nome[s] das tintas, como se moem, apurão, conservão, & compõem. fol. 1. 2ª Na segunda como se fazem diversas miscras, & de suas compusturas & nomes das cousas, & outras necessarias. fol. 8v. 3ª Na terceira, como se fazem algNJas tintas de novo, & como se conservao, para usar dellas. E assim maes de tres maneiras, de pegar ouro em Letras, fazer grude, ou colla, e outras cousas.
- Manufacture of Ceramic Bricks Using Recycled Brewing Spent KieselguhrPublication . Ferraz, Eduardo; Coroado, João; Silva, Joaquim Pedro; Gomes, Celso; Rocha, FernandoIn the brewing process, kieselguhr performs as a filtration medium and one generated by-product is a sludge containing kieselguhr, which is mainly composed of fragmented diatom frustules associated to organic material retained during the clarification process. The physic-mechanic tests were performed on assemblages with brick composition and brewing spent kieselguhr containing 3, 9, and 15 wt% incorporation levels of sludge, being extruded and dried (105ºC) before being submitted to slow firing at 900ºC, 950ºC, and 1000ºC. The obtained results showed that, even when at its maximum incorporation level, the spent kieselguhr for all firing temperatures do not cause important losses on the properties exhibited by the clay paste without kieselguhr incorporation and the best incorporation levels are 4.2 wt% when fired at 900ºC, 9.8 wt% when fired at 950ºC, and 13.4 wt% when fired at 1000ºC. When fired at 950ºC, 15 wt% addition of spent kieselguhr increased by 27% the open porosity and decreased by 10% the bulk density of the brick paste. Furthermore, physic-mechanic tests and ecotoxicity evaluation on semi-industrial brick manufactured with 9 wt% of brewing spent kieselguhr were accessed. The results do no show any constrain concerning mechanical properties, and the ecotoxicity evaluation shows the safety of the brewing spent kieselguhr incorporation in ceramic products.
- Ciência e Conservação: alguns problemas de uma relação frequentemente conflituosa, mas necessáriaPublication . Cruz, António João; Sousa, Gonçalo Vasconcelos e; Vieira, EduardaA relação entre a Ciência e a Conservação, no contexto mais amplo da aplicação de métodos laboratoriais ao estudo de obras de arte e outros bens culturais, tem-se desenvolvido de acordo com três modelos: solicitação ao laboratório, oferta do laboratório e colaboração. A relação, predominantemente, tem seguido os dois primeiros modelos, com implicações limitadas na área de Conservação e Restauro. Embora a colaboração seja mais vantajosa, ela enfrenta desafios de comunicação entre as duas culturas envolvidas, desafios estes agravados pelos avanços tecnológicos mais recentes. No entanto, mesmo diante dessas dificuldades, os conservadores-restauradores podem desempenhar um papel fundamental no processo de análise laboratorial.
- Sobre os materiais utilizados na talha da época barroca do noroeste de Portugal - primeiros resultadosPublication . Cruz, António João; Sousa, Gonçalo Vasconcelos e; Vieira, EduardaCom o objectivo de contribuir para o conhecimento da talha portuguesa do período barroco apresentam-se os primeiros resultados de um estudo de 18 retábulos pertencentes à cidade do Porto. Pretendeu-se identificar os materiais e as técnicas usadas nas camadas de gesso, de bolo e de douramento, usando microscopia óptica e microscopia electrónica de varrimento. Identificou-se anidrite e gesso com baixo teor de impurezas, bolo de boa qualidade e ligas metálicas com concentração de ouro quase sempre superior a 90%. Os dados obtidos até ao momento sugerem que as recomendações dos documentos da época terão sido seguidas na maioria dos casos.
- Regraxar or glazing: aspects of this technique in a group of Portuguese paintings attributed to Francisco João (active 1563 95)Publication . Melo, Helena Pinheiro de; Cruz, António João; Sanyova, Jana; Candeias, António; Mirão, José; Valadas, Sara