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- Limitations and obstacles on wood identification from sculptures - analysis of a set of gilded and polychromed flemish artworks from the 15th centuryPublication . Silva, José Luis; Barata, Carolina Sofia; Pissarra, JoséWood identification through its internal anatomy is a complex and time-consuming process, often leading to taxonomic results at genus level (sometimes only family). The identification of the wood support of artworks contains specific methodological requirements and various limitations that are normally not applied with the common histological methodology. Preparation of wood for microscopic examination requires samples with approximately 1 cm3. This is a volume that can conflict with ethical issues of intervention, namely the scale of the piece itself, the aesthetic and structural integrity or even the commercial value of the artwork. Because of these, besides other factors such as the presence of metal leaf, polychromies and varnishes, collecting usually becomes impractical. Also, the absence of any crack, fracture or perforation where collecting could be facilitated, or the presence of degraded or already intervened areas allowed for collecting, all contribute to hamper the identification of wooden artworks. In this paper, which is intended mainly for artwork restorers, we describe the alternatives and solutions that were explored to circumvent the limitations on the wood processing for identification, which allowed us to analyse and characterize a set of Flemish 15th century polychromed and gilded sculptures.
- Eighteenth century technological efficiency: the reuse of Brazilian sugar chest wood in Portuguese cabinet manufacturePublication . Bernal, Rocio Astrid; Valente, Adelina; Pissarra, JoséWe studied decorative Portuguese furniture from the 18th century Clérigos Church in Porto, to identify the woods used, to analyze their possible origin and understand the criteria for wood choice, according to sample location. We identified wood from Acacia sp., Castanea sativa, Couratari sp. and Dalbergia nigra. D. nigra, Acacia sp. and Couratari sp. may have arrived from Brazil, according to their natural distribution and the Portuguese colonial routes; C. sativa was abundant in the North Region of Portugal. In the 18th century, golden metal brass over black furniture was in fashion in Portuguese ecclesiastical cabinet making. Due to its dark colour, Dalbergia nigra was a desirable wood for the exposed structures of ecclesiastical furniture, such as top drawers and top tables. Couratari is a pale wood. Therefore, it was used in the inner structure of the drawers and legs. Acacia wood was also used in internal parts due to its durability. C. sativa was local and extensive; its wood was used in the inner structures, where it could not be seen. Marks were found in the Couratari wood, which indicated that the timber from chest boards employed to carry sugar from Brazil to Portugal was reused. The high silica content of Couratari wood makes it ideal for building “sugar chests”.
- Insights into phytoremediation solutions for environmental recoveryPublication . Samardjieva, Kalina A.; Pissarra, José; Castro, Paula ML; Tavares, FernandoOur environment is contaminated with organic and inorganic compounds released by anthropogenic activities that cause negative impacts on biological productivity and ecosystem sustainability and place human health at risk. Within the available remediation technologies, phytoremediation has emerged with high potential due to its reduced environmental impacts and economic costs. The research into phytoremediation has developed through a wide array of approaches, which also pertains to its inherent interdisciplinary characteristics, towards enhancing the potential of the technology for application in the field. Numerous patents present molecular solutions through which plants can be engineered to display improvements in key characteristics, such as the tolerance, uptake and accumulation of contaminants. The manipulation of plant growth and of the physico-chemical characteristics of the contaminated environments in order to enhance the remediation potential has also been the focus of several issued patents. This review attempts to highlight the most relevant patented advances in phytoremediation and to emphasise recent research efforts through which this green technology might be expected to develop into a commercially competitive alternative to other remediation methods.
- Osmotic dehydration of cut apple: mass transfer kinetics and microstructural changesPublication . Assis, F. R.; Pissarra, J.; Morais, R. M. S. C.; Morais, A. M. M. B.Apple cubes were osmotically dehydrated with 40 degrees Bx sucrose and sorbitol solutions. Light microscopy was used to observe the microstructure of fresh and osmotically dehydrated samples. Peleg's model could fit the experimental data and describe the mass transfer kinetics of water loss (WL) and solid gain (SG). The use the sorbitol as osmotic agent. the increase of temperature and concentration of the solution increased the WL during the osmotic dehydration. The average cellular parameters, area and perimeter (size), and circularity, elongation, roundness, and compactness (shape) of fresh samples were 14.281 +/- 6.65x10(3) mu m(2) and 0.486 mm, and 0.73, 1.56, 0.70, 0.83. respectively. The osmotically dehydrated samples presented a decrease in area, circularity, roundness and compactness and an increase in the elongation of the cells, and these changes were higher in samples treated with sorbitol.
- Wood identification of 18th century furniture. Interpreting wood naming inventoriesPublication . Bernal, Rocio Astrid; Valente, Adelina; Pissarra, JoséThe 18th century Portuguese church furniture represents an extraordinary richness recognised worldwide, which demands safeguarding and valorisation. The identification of the wood of furniture artworks is the most important component for its comprehension and preservation. In this work wood anatomical characters of an 18th century Portuguese decorative furniture set from the Colegiada de São Martinho de Cedofeita, in Porto, were analysed to identify the woods used for manufacturing and to clarify their common names. Furthermore, the objectives were to recognise some of the criteria for choice of wood as well as the source of each wood. The woods identified from 16 fragments belong to Apuleia sp., Acacia sp., Neolamarckia sp. and Castanea sativa. Apuleia sp. and Acacia sp. woods most likely arrived from Brazil, while the Neolamarckia sp. woods likely arrived from India and the C. sativa woods from Portugal. The results are in accordance with the known Portuguese colonial sea routes of the 15th -18th centuries. Interestingly the terms found in the inventories can refer to finishing methods instead to the name of the woods, as for instance “oil wood” can refer to “oiled wood” or “linseed oiled wood”. The species choice may be related to the mechanical properties of the wood as well as the original tree size. Two large planks of Acacia sp. were used for the top of the “Portuguese arcaz”, and Apuleia sp. was found on main structural elements of this set of furniture, suggesting that wood colour was also important. Woods from Neolamarckia sp. and C. sativa, were also identified, being Castanea wood present only in the most recent pieces of the furniture set.