RESUMO
Light microscopy is the conventional method used to investigate wood anatomy, identify the wood taxon, and assess its conservation state. It generally requires the mechanical cut of thin sections from a sample to obtain informative images. When dealing with wooden artworks or ancient remains (e.g., archaeological waterlogged wood), it is important to avoid sample destruction. In this work the efficacy of micro-magnetic resonance imaging (µ-MRI) to investigate the anatomy of waterlogged wood is assessed in comparison with light microscopy. Images along the three anatomical directions (transverse, tangential and radial) of six modern wood species and one archaeological specimen of waterlogged wood (from the Neolithic site "La Marmotta") were obtained both by µ-MRI and light microscopy. µ-MRI images were acquired virtually selecting 2D slices along the three wood anatomical directions. A 3D reconstruction was derived from 2D µ-MRI images. Conventional light microscopy histology was obtained by manually cutting thin sections. To the best of our knowledge, this is the first study in which high-resolution MR images and light microscopy images of the three anatomical directions of seven wood species are compared. The non-destructive µ-MRI approach allows to investigate the 2D and 3D topological organization of the whole waterlogged wood sample up to a resolution of 8 µm. Although the optical microscope attains higher image resolutions and remains superior in the observation of wood diagnostic characters, multi-parametric µ-MRI provides physiological investigation complementary to light microscopy, giving information concerning both a single section and the whole volume of the sample. The presented study may represent a starting point for further improvements of µ-MRI techniques applied to the non-destructive investigation of waterlogged wood samples, especially those of interest for cultural heritage.
Assuntos
Microscopia , Madeira , Imageamento por Ressonância Magnética , Arqueologia/métodosRESUMO
Plants contribute to increase our green space and to produce natural compounds and substances to be applied to many fields of human activity, from foods to pharmaceuticals, from cosmetics to environment. Sensor technology can contribute to ensure living conditions to plants starting from the monitoring of water mobility within soil. A sensor based on a gypsum crystal is here proposed and validated to check mobility of water in different kinds of soil.
Assuntos
Plantas , Solo , Sulfato de Cálcio/química , Humanos , Plantas/química , Solo/química , Tecnologia , Água/análise , Abastecimento de ÁguaRESUMO
The degradation of materials commonly starts on the surface of the object and proceeds towards inside through pores, increasing fractures and lesions. To restore mechanical and aesthetic characteristics, it is necessary by the application of consolidants to fill these weak points so that they become inaccessible to corrosive agents. Greater is the amount of consolidant that penetrates, greater the efficiency of the restoration. This is the limiting factor of many approaches which due to very tight pores result not fully successful. The consolidation under vacuum can help to pass these difficulties. So we have adopted it to restore Macco samples and tested to consolidate archaeological bones. The samples were consolidated by complete immersion under vacuum (-700 mm Hg), in a consolidant solution containing 8% w/V of diammonium phosphate. The success of the application to both the kind of samples is shown by microscope images, SEM-EDAX analysis, and weight variation.
Assuntos
VácuoRESUMO
This paper reports the analytical detection and energetic properties of a glucose-fed Direct Catalytic Fuel Cell (DCFC) operated in association with yeast cells (Saccharomyces Cerevisiae). The cell was tested in a potentiostatic mode, and the operating conditions were optimized to maximize the current produced by a given concentration of glucose. Results indicate that the DCFC is characterized by a glucose detection limit of the order to 21 mmol L-1. The cell was used to estimate the "pool" of carbohydrate content in commercial soft drinks. Furthermore, the use of different carbohydrates, such as fructose and sucrose, has been shown to result in a good current yield.
Assuntos
Fontes de Energia Bioelétrica , Saccharomyces cerevisiae/fisiologia , Etanol , Frutose , Glucose , SacaroseRESUMO
Research in restoration and conservation is directed vs. more sustainable working materials, methods and technologies. Electrophoretic removal, from porous material, of undesired stains due to charged species is theoretically an interesting alternative to chemical cleaning methods, but the lack of specific and comprehensive research work leads to controversial opinions about the efficiency and the needed harmfulness for the treated objects. In this work paper, samples with artificial rust stains were subjected to electrophoretic cleaning treatments in mineral water as electrolyte. Treatments were carried out either in a bath by complete sample immersion between the distanced electrodes or by sample wetting and sandwiching between the electrodes. Evaluation of cleaning efficiency and treatment effects was based on colour change measurements (image analysis of scanned paper samples before and after the treatment and by colorimetric data via spectrophotometric measurements), investigation of morphological changes by SEM observations and folding endurance measurements.